JP2009228827A - Elastic roller and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an elastic roller capable of stably manufacturing the high-quality elastic roller, by preventing image failure by restraining appearance failure by a coating defect, and to provide the elastic roller having an uniform surface layer. <P>SOLUTION: This manufacturing method of the elastic roller comprises a shaft core body, an elastic layer formed on the outer periphery of the shaft core body, and a surface layer formed on the outer periphery of the elastic layer. The manufacturing method of the elastic roller comprises an application process of applying paint for forming the surface layer on the elastic layer, and comprises a process of adjusting surface free energy of an outside surface of the elastic layer to 10 mN/m or more before the application process. The elastic roller is manufactured by this method. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an elastic roller used by being mounted on an image forming apparatus. More particularly, the present invention relates to an elastic roller such as a charging roller used in an image forming apparatus using an electrophotographic process such as an LBP (Laser Beam Printer), an OA apparatus such as a copying machine and a facsimile.

  The thin film layer is formed on the surface of the elastic layer by the ring head coating method. The paint is uniformly discharged from the slit that is opened over the entire circumference of the ring head inner peripheral surface, and the ring head and the elastic member move relatively. By doing so, the thin film layer can be applied at a high speed. However, when a low-viscosity paint is applied to form a thin film layer, the film formation state of the thin film layer depends on the compatibility between the elastic member surface and the paint, and the paint unevenness is particularly affected by the wettability of the elastic member surface and the paint. May occur.

  When an elastic roller is used as a charging roller in an image forming apparatus such as an electrophotographic apparatus or a copying machine, the elastic roller is brought into pressure contact with a photosensitive drum, and the surface is uniformly charged with a predetermined polarity potential. Therefore, the outer diameter accuracy of the elastic roller, the uniformity of the surface roughness, and the uniformity of the surface layer formed on the elastic layer are important. However, if the paint is uneven as described above, the surface layer becomes non-uniform, resulting in variations in the resistance value of the elastic roller, and the photosensitive drum surface cannot be uniformly charged, resulting in image defects. There is.

Here, a method of adjusting the water contact angle of the surface to be coated has been studied as a countermeasure against the above-described uneven coating of the photosensitive drum (see Patent Document 1). In addition, in a conductive member having an elastic layer and a coating layer around a columnar conductive support, there is a method of adjusting the surface water contact angle to be applied as a measure to eliminate the difference in the upper and lower film thickness due to dripping during dip coating. It has been studied (see Patent Document 2).
JP 2003-322988 A JP 2007-105625 A

  However, when applying low-viscosity paint to form a thin film layer, it is more susceptible to the wettability of the elastic member surface and paint, so the water contact angle alone is not sufficient to express wettability. There is.

  Accordingly, an object of the present invention is to provide an elastic roller manufacturing method capable of preventing image defects by suppressing appearance defects due to coating defects and stably manufacturing high-quality elastic rollers.

  Another object of the present invention is to provide an elastic roller with a uniform surface layer.

According to the present invention, there is provided a method for producing an elastic roller having a shaft core body, an elastic layer formed on the outer periphery of the shaft core body, and a surface layer formed on the outer periphery of the elastic layer. In the manufacturing method of the elastic roller which has the application process which applies the paint of the above on an elastic layer,
Prior to the coating process,
There is provided a method for producing an elastic roller, comprising the step of adjusting the surface free energy of the surface of the elastic layer to which the coating material is applied in the applying step to 10 mN / m or more.

  According to the present invention, an elastic roller manufactured by the above-described elastic roller manufacturing method is provided.

  According to the present invention, there is provided an elastic roller manufacturing method capable of preventing image defects by suppressing appearance defects due to coating defects and stably manufacturing high-quality elastic rollers.

  The present invention also provides an elastic roller having a uniform surface layer.

  The present invention relates to a method of manufacturing an elastic roller having a shaft core, an elastic layer formed on the outer periphery thereof, and a surface layer formed on the outer periphery of the elastic layer. This method includes a step of applying a coating material for forming a surface layer on the elastic layer (application step).

  In this manufacturing method, as a step preceding the coating step, the surface free energy of the outer surface of the elastic layer (the surface on which the coating is applied in the coating step) is adjusted to 10 mN / m or more (hereinafter, depending on the case, the surface free energy adjustment) Process).

  By adjusting the surface free energy in this way, image defects can be prevented by suppressing appearance defects due to coating defects, and high-quality elastic rollers can be manufactured stably.

  An embodiment of the elastic roller according to the present invention will be described. This elastic roller has a cross-sectional structure shown in FIG. In FIG. 1, the elastic roller 1 includes a shaft core 1a, an elastic layer 1b, and a surface layer 1c. An elastic layer 1b is provided on the outer periphery of the shaft core 1a, and a surface layer 1c is provided on the outer periphery of the elastic layer 1b.

  Hereinafter, the method for producing an elastic roller according to the present invention will be described in more detail with reference to an example in which a coated surface layer is formed on the elastic layer by a surface free energy adjustment step on the surface of the elastic layer and a subsequent coating step after molding a rubber roller. . In the present specification, the “rubber roller” means that at the stage where the elastic layer is formed on the outer periphery of the shaft core body (before the surface layer is formed).

[Production of rubber roller]
First, as a method of manufacturing a rubber roller by forming an elastic layer on a shaft core body, for example, two cylindrical pieces concentrically holding a shaft core body are assembled in a cylindrical mold, and an elastic layer material is injected. There is injection molding in which a material is cured by post-heating to form a rubber roller. In addition, there is extrusion molding in which an elastic layer material is extruded into a tube shape, and then the shaft core body is covered with the tubular elastic layer material, or the shaft core body and the elastic layer material are integrally extruded to form an elastic roller. In addition, there are transfer molding, press molding, and the like. However, it is not particularly limited. In view of shortening the manufacturing time, extrusion molding in which a rubber roller is formed by extruding the elastic layer material integrally with the shaft core body is preferable.

  This extrusion molding can be performed by an extruder equipped with a crosshead. That is, the shaft core body fed by the shaft core body feed roller is inserted from the back of the cross head, and the cylindrical elastic layer material is integrally extruded simultaneously with the shaft core body. Thereafter, the rubber roller is obtained by cutting and removing the end portion of the elastic layer.

  As for the method of heating (curing) the rubber roller, any method such as a hot stove, a vulcanizing can, a hot platen, heating by far / near infrared rays, induction heating or the like may be used. Alternatively, a method may be used in which a rubber roller (before elastic layer curing) is pressed against a heated cylindrical or planar member while rotating.

  In some cases, dry grinding using a rotating grindstone may be performed after heating (curing) to obtain a desired roller shape and roller surface roughness.

  The rubber roller shaft core can be appropriately selected from known elastic roller shaft cores, but includes a stainless steel rod, a phosphor bronze rod, an aluminum rod, a heat-resistant material including a steel material such as nickel-plated SUM. A resin rod is preferred.

  Further, the elastic layer provided on the shaft core body can be a conductive elastic layer. Examples of rubber materials constituting such an elastic layer include natural rubber, butadiene rubber, hydrin rubber, styrene-butadiene rubber, nitrile rubber, ethylene-propylene rubber, butyl rubber, silicone rubber, urethane rubber, fluorine rubber, chlorine rubber, heat A plastic elastomer etc. are mentioned.

  In order to make the elastic layer conductive, a conductive agent can be dispersed in the elastic layer. Examples of the conductive agent include carbons such as carbon black and conductive carbon, metal powder, conductive fiber, semiconductive metal oxide powder such as tin oxide, and a mixture thereof.

[Surface free energy adjustment of elastic layer surface]
In the present invention, in order to adjust the surface free energy of the coated surface of the elastic layer, a method capable of changing the surface free energy without damaging the shape can be appropriately employed. For example, water cleaning, solvent cleaning, tape cleaning, ultraviolet irradiation, electron beam irradiation, or a combination of these methods can be employed.

  As an example, the water washing process of the elastic layer surface by injecting water from a washing nozzle and then ejecting gas from a drying nozzle to remove water droplets will be described below. The pressure of water to be injected is preferably 2 to 6 MPa, and the pressure of the gas to be injected is preferably 0.2 to 0.6 MPa. If the pressure of the water to be sprayed is in the above range, a component that exudes from the elastic layer or dirt that adheres when dry polishing using a rotating grindstone can be efficiently removed. Moreover, when the pressure of the gas to be injected is in the above range, a dry state that greatly affects the surface free energy of the elastic layer surface can be made suitable, and the surface free energy can be adjusted well.

  Examples of water used for washing include ion exchange water, purified water, ultrapure water, alkali ion water, superreducible water, tap water, and well water.

  As the gas used for drying, a chemically inert and stable gas is preferable. For example, air, nitrogen, helium, argon, etc. are mentioned.

  By the surface free energy adjustment step, the surface free energy of the elastic layer before the coating step is set to 10 mN / m. Conditions (such as the type of water and gas and the injection pressure) can be experimentally determined by the above-described treatment method so that the surface free energy of the elastic layer falls within this range.

  If the surface free energy of the elastic layer is 10 mN / m or more, the wettability between the elastic member surface and the coating material is suitable even when a low-viscosity coating material is applied to form a thin film layer (surface layer). Therefore, a coating layer with no coating defects does not occur and a surface layer free from coating defects is obtained.

  When the surface free energy of the elastic layer is less than 10 mN / m, when a low-viscosity paint is applied to form a thin film layer (surface layer), the surface of the elastic member and the paint are not well-suited during film formation. Uneven coating occurs, resulting in coating defects. When the surface free energy of the elastic layer is larger, the surface of the elastic member and the paint become more familiar at the time of film formation, so that a surface layer without uneven paint can be obtained. Therefore, the upper limit of the surface free energy is not particularly limited, and the value that can be taken by the material used for the elastic layer and the method for adjusting the surface free energy is experimentally determined.

  Here, the surface free energy of the elastic layer in the present invention is based on the theory of Kitazaki and Hata, the contact angles with water, diiodomethane and ethylene glycol are measured, and the surface free energy is calculated using these contact angles. is there. Even if the water contact angle is the same, the degree of paint unevenness may vary, but using surface free energy can more appropriately express the wettability of the elastic layer and paint, and the correspondence with paint unevenness it can.

[Method for forming surface layer]
Next, a method for applying a coating material for forming a surface layer (on the elastic layer) to the rubber roller by the ring head application method will be described in detail. However, the method is not limited to this, and a known method that can apply a paint on the elastic layer such as dip coating, spray coating, roll coating, blade coating, or the like can also be employed.

  In FIG. 2, 3 is a ring head for application, and 1d is a rubber roller in which an elastic layer 1b is formed on the peripheral surface of the shaft core 1a. Reference numeral 8 denotes a coated surface layer formed on the peripheral surface of the elastic layer 1b. Reference numeral 2 denotes a gripping member for gripping the rubber roller 1d. The gripping member forms part of a rubber roller transport unit that moves relative to the coating ring head 3.

  The rubber roller 1d is disposed so as to be concentric with the ring head 3 for application. Further, the rubber roller 1d is fixed to the holding member 2 of the rubber roller 1d and held in a vertical state. Further, the rubber roller 1d and the application slit 4 are arranged at a predetermined interval.

  First, paint is supplied to the liquid supply port 7 from a liquid supply means (not shown) outside the coating ring head 3 (not shown).

  The supplied paint is almost filled over the entire circumference of the liquid distribution chamber 6. Thereafter, the fluid flows toward the coating slit 4, but by passing through the liquid constricting part 5, the flow velocity is increased, and the coating material in the circumferential direction is made more uniform. And it discharges to the surface of the elastic layer 1b from the slit 4 for application | coating.

  The discharge speed of the coating material onto the surface of the rubber roller 1d is determined by the moving speed of the coating ring head 3 with respect to the rubber roller 1d. For example, when the moving speed of the coating ring head 3 with respect to the rubber roller 1d is 85 mm / s, the discharge speed of the paint onto the surface of the rubber roller 1d is preferably 0.013 mL / s or more and 0.053 mL / s or less. If the discharge speed of the paint is 0.013 mL / s or more, it is possible to suppress the running out of liquid, and if it is 0.053 mL / s or less, it is effective for suppressing dripping.

  Further, the discharge amount of the rubber roller 1d onto the surface of the gripping member 2 and the discharge amount onto the surface of the rubber roller 1d may be changed.

  For example, the discharge amount of the rubber roller 1d onto the surface of the elastic layer 1b can be calculated from a desired coating film thickness and the like, and the paint can be applied to the surface of the gripping member 2 of the rubber roller 1d with a discharge amount smaller than this. Thereby, it is possible to effectively prevent the paint from dripping from the gripping member 2 of the rubber roller 1d onto the surface of the rubber roller 1d.

  The width of the discharge port (slit) opened over the entire circumference of the inner peripheral surface of the coating ring head is preferably 0.01 mm or more and 1.0 mm or less, and is selected and determined by the liquid viscosity of the paint and the material added to the paint. .

  Further, regarding the surface layer of the elastic roller of the present invention, the layer thickness is preferably a thin film in terms of electrical characteristics or strength, and is preferably 10 nm or more and less than 1000 nm. When the thickness of the surface layer is 10 nm or more, a surface layer that satisfies the electrical characteristics and surface free energy characteristics as the surface layer can be easily obtained. Moreover, when the thickness of the surface layer is less than 1000 nm, it is easy to prevent the surface layer from following the elastic layer and cracking when the hardness of the surface layer is large.

  As the material for forming the surface layer, silicone-based, fluorine-based, urethane-based, acrylic-based, urethane-modified acrylic-based, and silicone-modified urethane-based materials are used. In particular, a material containing polysiloxane having a fluorinated alkyl group and an oxyalkylene group is preferable. Here, the content of the fluorinated alkyl group is preferably 15 mol% or less in order to suppress the occurrence of uneven coating because of the ease of conformation of the elastic layer and the paint. The lower limit of the content is not set from the viewpoint of easy compatibility of the elastic layer and the paint, but is preferably 1 mol% or more from the viewpoint of soiling properties when the elastic roller is used. The content of the fluorinated alkyl group is a value indicating the mol number of the fluorinated alkyl group with respect to the mol number of the polysiloxane as a percentage. As a method for obtaining the content of the fluorinated alkyl group, for example, Si-solid NMR is used, a measurement sample is inserted into a ceramic probe having a diameter of 7.5 mm, and measurement by a CP / MAS method is performed at room temperature (25 ° C.). can give.

  As a solvent that can be used for dissolving the surface layer forming material to obtain the surface layer forming coating material, a solvent having good solubility in the surface layer forming material can be used as appropriate. Examples thereof include alcohols such as ethanol and 2-butanol, ethyl acetate, methyl ethyl ketone, and the like, or a mixture thereof.

  Further, the viscosity of the coating is preferably low in order to suppress the occurrence of uneven coating because of the ease of conformation of the elastic layer and the coating, and the value of a B-type viscometer is 0.5 mPa · s to 2.0 mPa · s. The following is preferred.

  From the viewpoint of forming a thin film layer of 10 nm or more and less than 1000 nm and the solubility of the surface layer forming material, the concentration of the paint is preferably 50 to 99% by mass.

  Next, a method for curing the coated surface layer (uncured coated layer) formed by discharging paint on the rubber roller surface will be described. The coated surface layer may be heat cured. In this case, any method such as a hot stove, a hot platen, heating by far / near infrared rays, induction heating or the like may be used, or these heating methods may be used in combination. Moreover, you may make it harden | cure by irradiating an active energy ray, and hardening in a short time is attained in this case. The active energy ray may be an ultraviolet ray or an electron beam. In addition, when the coated surface layer is irradiated with active energy rays, the elastic layer is simultaneously modified and cured. In particular, in the case where the elastic layer is a rubber having a double bond, the effect of modification / curing by irradiation with active energy rays is large, and therefore it is preferable to cure the coated surface layer by irradiation with active energy rays.

  As described above, the surface layer can be formed on the outer periphery of the elastic layer by appropriately curing the coating layer after the coating step of applying the coating material for forming the surface layer on the elastic layer.

[Image forming apparatus]
The elastic roller obtained by the elastic roller manufacturing method of the present invention can be used as an electrophotographic member of an image forming apparatus such as a LBP (Laser Beam Printer), a copying machine, and a facsimile. Here, FIG. 3 shows a usage pattern when used as a charging roller. The image forming apparatus is a rotating drum type / transfer type electrophotographic apparatus, and 13 is an electrophotographic photosensitive member (photosensitive drum) as an image carrier, which rotates clockwise at a predetermined peripheral speed (process speed). Driven. The photosensitive drum 13 is uniformly charged at a predetermined polarity and potential (for example, −600 V) by a charging roller 14 to which a charging bias is applied from a power source E1 as a charging unit during the rotation process. Next, the exposure system 15 receives negative image exposure (analog exposure of the original image, digital scanning exposure) corresponding to the target image information, and an electrostatic latent image of the target image information is formed on the peripheral surface of the photosensitive drum. Thereafter, the electrostatic latent image is developed as a toner image by a toner developing roller 16 of a reversal developing method using minus toner. A transfer material is fed to a transfer portion between the photosensitive drum 13 and a transfer roller 17 as a transfer unit at a predetermined timing from a paper supply unit (not shown). For example, a transfer bias of about +2 to 3 KV is applied to the transfer roller 17 from the power source E2, and the toner image on the surface of the photosensitive drum 13 that has been reversely developed is sequentially transferred to the transfer material. The transfer material that has received the transfer of the toner image is separated from the surface of the photosensitive drum 13 and introduced into fixing means (not shown) to undergo image fixing processing. The surface of the photosensitive drum 13 after the transfer of the toner image is subjected to a removal process of adhering contaminants such as transfer residual toner by the cleaning unit 18 to be cleaned and repeatedly used for image formation. A bias voltage is applied to the toner developing roller 16 from the power source E3.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to these.

Defects on the appearance of the elastic roller surface layer formed in each example and comparative example (coating irregularity, dripping, etc.) were evaluated visually as follows.
Evaluation A: There are no defects such as uneven coating.
Evaluation B: There are almost no defects such as coating unevenness.
Evaluation C: There are defects such as coating unevenness.

Further, when the manufactured elastic roller is used as a charging roller, image defects are caused by incorporating the elastic roller into an electrophotographic cartridge and outputting a halftone image in an environment of 23 ° C. and a relative humidity of 60%. Was evaluated as follows.
Evaluation A: There are no defects such as image unevenness.
Evaluation B: There are almost no defects such as image unevenness, and there is no practical problem.
Evaluation C: There are defects such as image unevenness (practical defects).

Example 1
<Ring head>
In order to apply the coating material for forming the surface layer on the elastic layer, a ring head having the structure shown in FIG. 2 was used.

  The ring head 3 for application has an outer diameter of 42 mm and an inner diameter of 8.7 mm, and the discharge port (application slit) 4 opened to the entire circumference has a width of 0.1 mm.

<Production of rubber roller>
The following raw materials were kneaded with a pressure kneader for 15 minutes.
・ NBR (acrylonitrile-butadiene copolymer rubber) 100 parts by mass (trade name: “Nipol DN219”, manufactured by Nippon Zeon Co., Ltd.)
Carbon black 1 14 parts by mass (trade name: “Asahi HS-500”, manufactured by Asahi Carbon Co., Ltd.).
Carbon black 2 4 parts by mass (Product name: “Ketjen Black EC600JD”, manufactured by Lion Corporation)
-1 part by mass of zinc stearate-5 parts by mass of zinc oxide-30 parts by mass of calcium carbonate (trade name: "Nanox # 30", manufactured by Maruo Calcium Co., Ltd.).

  In addition to the product obtained by the kneading, 1 part by mass of a vulcanization accelerator (DM: di-2-benzothiazolyl disulfide), 3 parts by mass of a vulcanization accelerator (TBzTD: tetrabenzylthiuram disulfide) and a vulcanizing agent (Sulfur) 1.2 parts by mass was added. This was further kneaded with an open roll for 15 minutes to prepare an unvulcanized rubber composition.

  Next, a shaft core of a stainless steel rod having an outer diameter of 6 mm and a length of 252 mm was prepared. In the present specification, φ means a diameter.

  Here, the shaft core and the unvulcanized rubber composition were integrally extruded using a crosshead extruder to form a rubber roller. Thereafter, heat vulcanization was performed at 160 ° C. for 1 hour, and further, dry polishing using a rotating grindstone and cutting / removal processing of the end portion gave a rubber roller having an elastic layer thickness of 1.25 mm and an elastic layer length of 232 mm (rubber roller Outer diameter φ8.5 mm).

<Adjustment and measurement method of surface free energy>
The elastic layer is rotated at 10 s ⁻¹ while supporting both ends of the conductive support (shaft core) on which the elastic layer is formed, and high-pressure water is supplied to the outer peripheral surface of the elastic layer along the longitudinal direction of the elastic layer. The water was washed by spraying gas in the same manner as above. During water cleaning, the pressure of water sprayed from the cleaning nozzle was 5 MPa, and the pressure of gas sprayed from the drying nozzle was 0.5 MPa.

  Here, the contact angle for calculating the surface free energy was measured using a contact angle meter (trade name “DM300”, manufactured by Kyowa Interface Science Co., Ltd.). Under an environment of 23.5 ° C. and a relative humidity of 60%, about 1.0 μl each of water, ethylene glycol, and diiodomethane was dropped on the surface of the elastic layer washed with water, and the contact angle was measured. The surface free energy was calculated using analysis software (trade name “FAMAS”, manufactured by Kyowa Interface Science Co., Ltd.). The contact angle of the elastic layer was 113.7 ° for water, 90.0 ° for ethylene glycol, 72.7 ° for diiodomethane, and the surface free energy was 19.5 mN / m.

<Formation of surface layer>
The following raw materials were prepared.
Glycidoxypropyltriethoxysilane (GPTES): 12.47 g (0.045 mol).
Phenyltriethoxysilane (PhTES): 43.08 g (0.179 mol).
-Hexyltrimethoxysilane (HeTMS): 13.21 g (0.064 mol).
Tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane (FTS, carbon number 6 of perfluoroalkyl group): 16.32 g (0.032 mol)
-Water: 25.93g.
-Ethanol: 74.16g.

  After mixing the raw materials, the mixture was stirred at room temperature and then heated to reflux for 24 hours to hydrolyze and condense the hydrolyzable silane compound to obtain a hydrolyzable condensate (polysiloxane). This hydrolyzable condensate (polysiloxane) was added to a mixed solvent of 2-butanol / ethanol (2-butanol / ethanol = 10/65 (mass ratio)). Thus, a hydrolyzable condensate (polysiloxane) -containing alcohol solution having a solid content of 7% by mass was prepared. 0.35 g of an aromatic sulfonium salt (trade name: Adekaoptomer SP-150, manufactured by Asahi Denka Kogyo Co., Ltd.) as a photocationic polymerization initiator for 100 g of this hydrolyzable condensate (polysiloxane) -containing alcohol solution. ) Was added. Furthermore, it diluted with ethanol so that it might become solid content 2.0 mass%, and the coating liquid (coating material for surface layer formation) for thin film layers was prepared. At this time, the fluorinated alkyl group content in the hydrolyzable condensate (polysiloxane) was 10 mol%. The viscosity of the coating solution was 0.8 mPa · s when measured using a B-type viscometer (trade name “VDL type”, manufactured by Shibaura System Co., Ltd.) at a liquid temperature of 23.5 ° C.

  Place the rubber roller prepared earlier so that it is concentric with the ring head, supply the paint prepared earlier to the liquid supply port of the ring head, and form a coating surface layer on the peripheral surface of the elastic layer of the rubber roller did.

  The ring head was vertically moved at a constant speed of 85 mm / s with respect to the surface of the rubber roller, and at the same time, the paint was applied at a discharge speed of 0.023 mL / s.

Thereafter, ultraviolet irradiation with a low-pressure mercury lamp (manufactured by Harrison Toshiba Lighting) was performed for 5 minutes. Regarding the low-pressure mercury lamp, the ultraviolet ray mainly represented by a wavelength of 254 nm was used, and the ultraviolet ray integrated light quantity at this time was about 10,000 mJ / cm ² (the ultraviolet ray intensity was 35 mW / cm ² ).

  As a result of visual evaluation of the elastic roller surface of this example, no appearance defect due to coating unevenness was found on the elastic roller surface (evaluation: A).

  Further, this elastic roller was assembled as a charging roller in an electrophotographic image forming apparatus having the structure shown in FIG. Then, both ends of the photosensitive drum were pressed in a state where a load of 500 g was applied, and initial image evaluation was performed using a halftone image in an environment of 23.5 ° C. and a relative humidity of 60%. In this evaluation, a good image was obtained with the elastic roller of this example (evaluation: A). The results are shown in Table 1.

  Table 1 shows the surface free energy of the elastic layer surface, the content of alkyl fluoride group in the polysiloxane, the viscosity of the coating material for forming the surface layer, the visual evaluation result of the elastic roller surface, and the initial image evaluation result. It is shown.

(Example 2)
<Production of rubber roller>
A rubber roller was produced in the same manner as in Example 1.

<Adjustment of surface free energy>
The surface free energy was adjusted in the same manner as in Example 1 except that the pressure of the gas injected from the drying nozzle in water washing was 0.35 MPa. At that time, the contact angle of the elastic layer was 109.4 ° for water, 82.8 ° for ethylene glycol, 69.9 ° for diiodomethane, and the surface free energy was 23.1 mN / m.

<Formation of surface layer>
A surface layer was formed in the same manner as in Example 1.

  As a result of visual evaluation of the elastic roller surface of this example, no appearance defect due to coating unevenness was found on the elastic roller surface (evaluation: A).

  Furthermore, initial image evaluation was performed in the same manner as in Example 1 using this elastic roller. In this evaluation, the elastic roller of this example was able to obtain a good image (evaluation: A). The results are shown in Table 1.

(Example 3)
<Production of rubber roller>
A rubber roller was produced in the same manner as in Example 1.

<Adjustment of surface free energy>
The surface free energy was adjusted in the same manner as in Example 1 except that the pressure of water sprayed from the cleaning nozzle in water cleaning was 3 MPa. At that time, the contact angle of the elastic layer was 119.0 ° for water, 90.3 ° for ethylene glycol, 74.1 ° for diiodomethane, and the surface free energy was 17.7 mN / m.

<Formation of surface layer>
A surface layer was formed in the same manner as in Example 1.

  As a result of visual evaluation of the elastic roller surface of this example, no appearance defect due to coating unevenness was found on the elastic roller surface (evaluation: A).

  Furthermore, initial image evaluation was performed in the same manner as in Example 1 using this elastic roller. In this evaluation, the elastic roller of this example was able to obtain a good image (evaluation: A). The results are shown in Table 1.

Example 4
<Production of rubber roller>
A rubber roller was produced in the same manner as in Example 1.

<Adjustment of surface free energy>
The surface free energy was adjusted in the same manner as in Example 1 except that the pressure of water sprayed from the cleaning nozzle in water cleaning was 3 MPa and the pressure of the gas sprayed from the drying nozzle was 0.35 MPa. At that time, the contact angle of the elastic layer was 119.1 ° for water, 87.2 ° for ethylene glycol, 72.9 ° for diiodomethane, and the surface free energy was 18.7 mN / m.

<Formation of surface layer>
A surface layer was formed in the same manner as in Example 1.

  As a result of visual evaluation of the elastic roller surface of this example, no appearance defect due to coating unevenness was found on the elastic roller surface (evaluation: A).

  Furthermore, initial image evaluation was performed in the same manner as in Example 1 using this elastic roller. In this evaluation, the elastic roller of this example was able to obtain a good image (evaluation: A). The results are shown in Table 1.

(Example 5)
<Production of rubber roller>
A rubber roller was produced in the same manner as in Example 1.

<Adjustment of surface free energy>
The surface free energy was adjusted in the same manner as in Example 1 except that the pressure of water sprayed from the cleaning nozzle in water cleaning was 2 MPa and the pressure of the gas sprayed from the drying nozzle was 0.6 MPa. At that time, the contact angle of the elastic layer was 120.2 ° for water, 102.4 ° for ethylene glycol, 94.5 ° for diiodomethane, and the surface free energy was 10.4 mN / m.

<Formation of surface layer>
A surface layer was formed in the same manner as in Example 1.

  As a result of visual evaluation of the elastic roller surface of this example, no appearance defect due to coating unevenness was found on the elastic roller surface (evaluation: A).

  Furthermore, initial image evaluation was performed in the same manner as in Example 1 using this elastic roller. In this evaluation, the elastic roller of this example was able to obtain a good image (evaluation: A). The results are shown in Table 1.

(Example 6)
<Production of rubber roller>
A rubber roller was produced in the same manner as in Example 1.

<Adjustment of surface free energy>
The surface free energy was adjusted in the same manner as in Example 2. At that time, the contact angle of the elastic layer was 109.4 ° for water, 82.8 ° for ethylene glycol, 69.9 ° for diiodomethane, and the surface free energy was 23.1 mN / m.

<Formation of surface layer>
In the same manner as in Example 1, a hydrolyzable condensate (polysiloxane) -containing alcohol solution having a solid content of 7% by mass was prepared. 0.35 g of an aromatic sulfonium salt (trade name: Adekaoptomer SP-150, manufactured by Asahi Denka Kogyo Co., Ltd.) as a photocationic polymerization initiator for 100 g of this hydrolyzable condensate (polysiloxane) -containing alcohol solution. ) Was added. Furthermore, it diluted with ethanol so that it might become 0.5 mass% of solid content, and the coating liquid for thin film layers was prepared. At this time, the fluorinated alkyl group content in the hydrolyzable condensate (polysiloxane) is 10 mol%. The viscosity of the coating solution was 0.5 mPa · s at a solution temperature of 23.5 ° C.

  Subsequently, a surface layer was formed in the same manner as in Example 1 using the prepared coating liquid for the thin film layer (coating material for forming the surface layer).

  As a result of visual evaluation of the elastic roller surface of this example, no appearance defect due to coating unevenness was found on the elastic roller surface (evaluation: A).

  Furthermore, initial image evaluation was performed in the same manner as in Example 1 using this elastic roller. In this evaluation, the elastic roller of this example was able to obtain a good image (evaluation: A). The results are shown in Table 1.

(Example 7)
<Production of rubber roller>
A rubber roller was produced in the same manner as in Example 1.

<Adjustment of surface free energy>
The surface free energy was adjusted in the same manner as in Example 2. At that time, the contact angle of the elastic layer was 109.4 ° for water, 82.8 ° for ethylene glycol, 69.9 ° for diiodomethane, and the surface free energy was 23.1 mN / m.

<Formation of surface layer>
In the same manner as in Example 1, a hydrolyzable condensate (polysiloxane) -containing alcohol solution having a solid content of 7% by mass was prepared. 0.35 g of an aromatic sulfonium salt (trade name: Adekaoptomer SP-150, manufactured by Asahi Denka Kogyo Co., Ltd.) as a photocationic polymerization initiator for 100 g of this hydrolyzable condensate (polysiloxane) -containing alcohol solution. ) Was added. At this time, the fluorinated alkyl group content in the hydrolyzable condensate (polysiloxane) is 10 mol%. The viscosity of the coating solution was 1.9 mPa · s at a solution temperature of 23.5 ° C.

  Subsequently, a surface layer was formed in the same manner as in Example 1 using the prepared coating liquid for the thin film layer (coating material for forming the surface layer).

  As a result of visual evaluation of the elastic roller surface of this example, no appearance defect due to coating unevenness was found on the elastic roller surface (evaluation: A).

  Furthermore, initial image evaluation was performed in the same manner as in Example 1 using this elastic roller. In this evaluation, the elastic roller of this example was able to obtain a good image (evaluation: A). The results are shown in Table 1.

(Example 8)
<Production of rubber roller>
A rubber roller was produced in the same manner as in Example 1.

<Adjustment of surface free energy>
The surface free energy was adjusted in the same manner as in Example 2. At that time, the contact angle of the elastic layer was 109.4 ° for water, 82.8 ° for ethylene glycol, 69.9 ° for diiodomethane, and the surface free energy was 23.1 mN / m.

<Formation of surface layer>
The following raw materials were prepared.
-Glycidoxypropyltriethoxysilane (GPTES): 11.58 g (0.042 mol).
-Phenyltriethoxysilane (PhTES): 40.00 g (0.166 mol).
-Hexyltrimethoxysilane (HeTMS): 13.21 g (0.064 mol).
Tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane (FTS, carbon number of perfluoroalkyl group 6): 24.48 g (0.048 mol)
-Water: 25.93g.
-Ethanol: 74.16g.

  A hydrolyzable condensate (polysiloxane) -containing alcohol solution having a solid content of 7% by mass was prepared in the same manner as in Example 1 except that these were used as raw materials. To 100 g of this hydrolyzable condensate-containing alcohol solution, 0.35 g of an aromatic sulfonium salt (trade name: Adekaoptomer SP-150, manufactured by Asahi Denka Kogyo Co., Ltd.) as a photocationic polymerization initiator was added. . Furthermore, it diluted with ethanol so that it might become 0.5 mass% of solid content, and the coating liquid for thin film layers was prepared. At this time, the fluorinated alkyl group content in the hydrolyzable condensate (polysiloxane) is 15 mol%. The viscosity of the coating solution was 0.3 mPa · s at a solution temperature of 23.5 ° C.

  Subsequently, a surface layer was formed in the same manner as in Example 1 using the prepared coating liquid for the thin film layer (coating material for forming the surface layer).

  As a result of visual evaluation of the elastic roller surface of this example, the elastic roller surface had almost no appearance defect due to uneven coating (evaluation: B).

  Furthermore, initial image evaluation was performed in the same manner as in Example 1 using this elastic roller. In this evaluation, the elastic roller of this example had almost no image unevenness and there was no practical problem (evaluation: B). The results are shown in Table 1.

Example 9
<Production of rubber roller>
A rubber roller was produced in the same manner as in Example 1.

<Adjustment of surface free energy>
The surface free energy was adjusted in the same manner as in Example 2. At that time, the contact angle of the elastic layer was 109.4 ° for water, 82.8 ° for ethylene glycol, 69.9 ° for diiodomethane, and the surface free energy was 23.1 mN / m.

<Formation of surface layer>
The following raw materials were prepared.
-Glycidoxypropyltriethoxysilane (GPTES): 11.23 g (0.040 mol).
-Phenyltriethoxysilane (PhTES): 38.77 g (0.161 mol).
-Hexyltrimethoxysilane (HeTMS): 13.21 g (0.064 mol).
Tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane (FTS, carbon number 6 of perfluoroalkyl group): 27.74 g (0.054 mol)
-Water: 25.93g.
-Ethanol: 74.16g.

  A coating solution for the thin film layer (coating for forming the surface layer) was prepared in the same manner as in Example 1 except that these were used as raw materials. At this time, the fluorinated alkyl group content in the hydrolyzable condensate (polysiloxane) is 17 mol%. The viscosity of the coating solution was 0.7 mPa · s at a solution temperature of 23.5 ° C.

  A surface layer was formed in the same manner as in Example 1 using the prepared coating liquid for thin film layer (coating material for forming the surface layer).

  As a result of visual evaluation of the elastic roller surface of this example, the elastic roller surface had almost no appearance defect due to uneven coating (evaluation: B).

  Furthermore, initial image evaluation was performed in the same manner as in Example 1 using this elastic roller. In this evaluation, the elastic roller of this example had almost no image unevenness and there was no practical problem (evaluation: B). The results are shown in Table 1.

(Example 10)
<Production of rubber roller>
A rubber roller was produced in the same manner as in Example 1.

<Adjustment of surface free energy>
The surface free energy was adjusted in the same manner as in Example 2. At that time, the contact angle of the elastic layer was 109.4 ° for water, 82.8 ° for ethylene glycol, 69.9 ° for diiodomethane, and the surface free energy was 23.1 mN / m.

<Formation of surface layer>
In the same manner as in Example 1, a hydrolyzable condensate-containing alcohol solution having a solid content of 10% by mass was prepared. 0.5 g of an aromatic sulfonium salt (trade name: Adekaoptomer SP-150, manufactured by Asahi Denka Kogyo Co., Ltd.) as a photocationic polymerization initiator was added to 100 g of this hydrolyzable condensate-containing alcohol solution. . At this time, the fluorinated alkyl group content in the hydrolyzable condensate (polysiloxane) is 10 mol%. The viscosity of the coating solution was 2.1 mPa · s at a solution temperature of 23.5 ° C.

  Subsequently, a surface layer was formed in the same manner as in Example 1 using the coating solution for the thin film layer (coating material for forming the surface layer).

  As a result of visual evaluation of the elastic roller surface of this example, the elastic roller surface had almost no appearance defect due to uneven coating (evaluation: B).

  Furthermore, initial image evaluation was performed in the same manner as in Example 1 using this elastic roller. In this evaluation, the elastic roller of this example had almost no image unevenness and there was no practical problem (evaluation: B). The results are shown in Table 1.

(Comparative Example 1)
<Production of rubber roller>
A rubber roller was produced in the same manner as in Example 1.

<Adjustment of surface free energy>
The surface free energy was adjusted in the same manner as in Example 1 except that the pressure of water sprayed from the cleaning nozzle in water cleaning was 2 MPa and the pressure of the gas sprayed from the drying nozzle was 1.0 MPa. At that time, the contact angle of the elastic layer was 120.7 ° for water, 106.7 ° for ethylene glycol, 98.5 ° for diiodomethane, and the surface free energy was 8.7 mN / m.

<Formation of surface layer>
A surface layer was formed in the same manner as in Example 1.

  As a result of visual evaluation of the elastic roller surface of this example, the elastic roller surface had defects such as coating unevenness (evaluation: C).

  Furthermore, initial image evaluation was performed in the same manner as in Example 1 using this elastic roller. In this evaluation, the elastic roller of this example had defects such as image unevenness and was a practical problem (evaluation: C). The results are shown in Table 1.

It is a typical sectional view of an elastic roller. It is a schematic diagram (sectional drawing) for demonstrating the ring head application | coating method. 1 is a schematic diagram illustrating an outline of an image forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Elastic roller 1a Shaft core 1b Elastic layer 1c Surface layer 1d Rubber roller 2 Rubber roller gripping member (rubber roller conveying means)
3 Ring head for application 4 Discharge port (slit for application) opened all around
5 Liquid constriction section 6 Liquid distribution chamber 7 Liquid supply port 8 Coating surface layer 13 Electrophotographic photosensitive member (photosensitive drum)
14 Charging roller (charging means)
15 Exposure system 16 Developing roller (developing means)
17 Transfer roller (transfer means)
18 Cleaning means E1, E2, E3 Power supply for bias application

Claims (5)

A method of manufacturing an elastic roller having a shaft core body, an elastic layer formed on the outer periphery of the shaft core body, and a surface layer formed on the outer periphery of the elastic layer. In the method of manufacturing an elastic roller having a coating process of coating on a layer,
Prior to the coating process,
A method for producing an elastic roller, comprising the step of adjusting the surface free energy of the surface of the elastic layer to which a coating material is applied in the applying step to 10 mN / m or more. The paint for forming the surface layer is
2. The production of an elastic roller according to claim 1, comprising a polysiloxane having a fluorinated alkyl group and an oxyalkylene group, and wherein the content of the fluorinated alkyl group in the polysiloxane is 15 mol% or less. Method. 3. The method for producing an elastic roller according to claim 1, wherein a viscosity of the coating material for forming the surface layer is 0.5 mPa · s or more and 2.0 mPa · s or less. 4. The method for producing an elastic roller according to claim 1, wherein in the coating step, coating is performed by a ring head coating method.   The elastic roller manufactured by the manufacturing method of the elastic roller in any one of Claim 1 to 4.

Images