JP4946043B2 - Cylindrical member, manufacturing method thereof, and image forming apparatus - Google Patents

Description

  The present invention relates to a polyamide-imide cylindrical member used in an image forming apparatus using an electrostatic copying method such as a copying machine or a printer, a manufacturing method thereof, and an image forming apparatus.

An image forming apparatus using an electrostatic copying system forms a uniform charge on an image carrier made of a photoconductive photosensitive member, and forms an electrostatic latent image with a laser beam or the like that modulates an image signal. The electrostatic latent image is developed with charged toner to obtain a visualized toner image.
For example, an image forming apparatus is disclosed in which a required reproduced image is obtained by electrostatically transferring the toner image via an intermediate transfer member (see, for example, Patent Document 1).

  The intermediate transfer material used in the image forming apparatus adopting the intermediate transfer method may be a conductive endless belt of a thermoplastic resin such as polycarbonate resin, polyvinylidene fluoride, polyalkylene phthalate, polyimide resin, or wholly aromatic. Proposals using polyamide resins have been made.

  Among them, wholly aromatic polyimide resins are strong in strength and are preferably used for transfer members, but have a problem of high cost. In order to reduce the cost, it is known to use a polyamide-imide resin into which an amide group is introduced. In Patent Document 2 below, a belt using polyamide-imide has good creep resistance, compared with a polyimide resin. Although it has been cited as an advantage that there is no heat shrinkage, a heating time of at least 3 hours or more is necessary to obtain resistance uniformity, and there is a problem in productivity. Similarly, it takes 9 hours to mix 18% by mass (22 phr) of carbon black having a pH of 4 and a volatile content of 3.5% in the polyamideimide resin described in Patent Document 3 below.

  In addition, when carbon black having a pH of 3 and a volatile content of 14% in Patent Document 4 below is mixed with 18 phr polyamideimide resin by a homogenizer and ultrasonic waves, the process time is shortened to 2 hours, but the resistance variation is large. Further, it is described that in this mixing method, the original mechanical properties of the binder resin are lost when dispersed for 30 phr or more.

  Patent Document 5 below exemplifies a polyamide imide resin mixed with 20 phr of carbon black of ph8 and volatile fraction of 0.5 and passed through a static mixer at a pressure of 100 MPa. However, since the resistance uniformity was poor and the surface property was poor, it could not be used as a cylindrical member for electrostatic copying.

On the other hand, the polyamide-imide resin has a problem that the folding resistance is worse than that of the polyimide resin and breaks while being used. In the following Patent Document 6, it is described that a belt having excellent folding resistance can be obtained by adding polyalkylene terephthalate to a thermoplastic resin (including polyamide-imide resin) having a tensile modulus of elasticity of 15000 Kgf / cm ² or more. However, in order to produce a cylindrical member with this combination, extrusion molding with inferior shape accuracy and film thickness accuracy is required, and it is difficult to use as a cylindrical member for electrostatic copying.
JP-A-62-206567 Japanese Patent No. 3218199 JP 2000-338789 A JP 2000-309712 A JP 2001-265130 A Japanese Patent Laid-Open No. 2001-34083

This invention is made | formed in view of the above conventional trouble, and makes it a subject to achieve the following objectives. That is,
An object of the present invention is to provide a cylindrical member having high productivity, good resistance uniformity and good folding resistance, and a method for manufacturing the same.
Another object of the present invention is to provide an image forming apparatus capable of forming a high-quality image.

As a result of intensive studies on the above-mentioned conventional problems, the present inventors have added uniform resistance to the polyamide-imide resin by adding oxidized carbon black having a pH of 5 or less and a volatile content of 5% or more and 15% or less to 30 phr or more and 50 phr or less. As a result, the present invention has been completed. That is, the present invention
<1> A solvent solution containing a solvent-soluble polyamideimide resin is mixed with an oxidation-treated carbon black having a pH of 5 or less and a volatile content of 5% or more and 15% or less, and then containing the oxidation-treated carbon black. A cylindrical member manufactured by dividing the solvent solution into two or more, passing the orifice at a pressure of 150 MPa or more, and colliding with each other, wherein the content of the oxidized carbon black is A cylinder characterized in that it is 30 to 50 parts by mass with respect to 100 parts by mass of a solvent-soluble polyamideimide resin, and has a folding resistance of 100 or more according to the MIT test method applied with a load of 10N. It is a shaped member.
<2> plane fluctuation width of the front surface resistivity common logarithm is a cylindrical member according to the less than 0.3 <1>.
<3> is a cylindrical member according to further the containing elastic material <1> or <2>.
< 4 > The cylindrical member according to < 3 >, wherein the elastic material is a solvent-soluble thermoplastic elastomer.
<5> is an image forming apparatus including a cylindrical member according to any one of <1> to <4>.
<6> the solvent solution containing a Solvent-soluble polyamide-imide resins, pH 5 or less and and 30 mass oxidized carbon black volatile content of 15% 5% to less with respect to the polyamide-imide resin 100 parts by weight The solvent solution containing the oxidized carbon black is divided into two or more and then passed through an orifice at a pressure of 150 MPa or more and made to collide with each other. It is a manufacturing method of the cylindrical member made into.

According to the present invention, it is possible to provide a cylindrical member having high productivity, good resistance uniformity and good folding resistance, and a method for manufacturing the same.
Further, according to the present invention, it is possible to provide an image forming apparatus capable of forming a high-quality image.

The cylindrical member of the present invention contains a polyamide-imide resin and an oxidation-treated carbon black having a pH of 5 or less and a volatile content of 5% or more and 15% or less. 30 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the imide resin, and the number of folding resistances by the MIT test method applied with a load of 10 N is 100 times or more.
Hereinafter, the cylindrical member of the present invention and the manufacturing method thereof will be described first.

<Cylindrical member and manufacturing method thereof>
The cylindrical member of the present invention is mainly composed of polyamideimide resin, and the content of oxidized carbon black having a pH of 5 or less and a volatile content of 5% or more and 15% or less is 100 parts by mass of the polyamideimide resin. On the other hand, it is 30 parts by mass or more and 50 parts by mass or less, and the number of folding resistances by the MIT test method applied with a load of 10 N is 100 times or more. In the present invention, the oxidation-treated carbon black having a pH of 5 or less and a volatile content of 5% or more and 15% or less is used because it is easy to disperse due to the functional group on the surface. A cylindrical member with good resistance uniformity and good productivity can be obtained by adding a large amount of not less than 50 parts by mass and eliminating the uneven distribution of oxidized carbon black. Polyamideimide resin is not only low-cost, but also has an amide group, so it has good carbon dispersibility, can increase the amount of carbon filling compared to a cylindrical cylindrical member, and has a smaller resistance variation. A shaped member can be obtained.

-Polyamideimide resin-
As the polyamideimide resin, various known ones can be used, but a solvent-soluble polyamideimide resin is preferable. Examples of the polyamideimide solvent include aprotic polar solvents such as N-methylpyrrolidone, N, N-dimethylacetamide, and acetamide. In addition, although the density | concentration, viscosity, etc. of the solution of a polyamidoimide resin are selected suitably, it is preferable that solid content concentration is 10-40 mass% and a viscosity is 1-1000 Pa.s.

-Oxidized carbon black-
Oxidized carbon black can be produced by oxidizing carbon black to give a carboxyl group, a quinone group, a lactone group, a hydroxyl group or the like to the surface. This oxidation treatment is an air oxidation method in which contact is made with air in a high-temperature atmosphere to react, a method of reacting with nitrogen oxides or ozone at room temperature, and air oxidation at high temperature, followed by ozone oxidation at a low temperature. It can be performed by a method or the like. Specifically, the oxidized carbon black can be produced by a contact method. Examples of the contact method include a channel method and a gas black method. Oxidized carbon black can also be produced by a furnace black method using gas or oil as a raw material. If necessary, after these treatments, a liquid phase oxidation treatment with nitric acid or the like may be performed. In addition, acidic carbon black can adjust pH by performing the above-mentioned liquid phase acid treatment to what was manufactured by the closed-type furnace method. For this reason, the carbon black obtained by the furnace method manufacturing and adjusted to have a pH of 5 or less by the post-treatment is also considered to be included in the present invention.

  In the present invention, the oxidation-treated carbon black has a pH value of 5 or less, preferably pH 4.5 or less, and more preferably pH 4.0 or less. Oxidized carbon having a pH of 5 or lower has oxygen-containing functional groups such as a carboxyl group, a hydroxyl group, a quinone group, and a lactone group on the surface, so that it has good dispersibility in the resin and good dispersion stability, and is semiconductive. The resistance variation of the conductive polyimide endless belt can be reduced, and the electric field dependency is also reduced, making it difficult for electric field concentration due to transfer voltage to occur.

  Here, pH is calculated | required by adjusting the aqueous suspension of carbon black and measuring with a glass electrode. Moreover, pH of acidic carbon black can be adjusted with conditions, such as processing temperature in an oxidation treatment process, and processing time.

  In the present invention, the oxidized carbon black has a volatile content of 5% or more and 15% or less (preferably 7% or more and 15% or less). When the volatile fraction is less than 5%, the effect of the oxygen-containing functional group attached to the surface is lost, and the dispersibility in the binder resin may be reduced. On the other hand, when the content is higher than 15%, there may be a problem that the appearance of the obtained molded product is deteriorated due to an increase in water adsorbed on the oxygen-containing functional group on the surface. Therefore, the dispersion | distribution in binder resin can be made more favorable by making a volatile content into the said range. This volatile content can be determined by the ratio of organic volatile components (carboxyl group, hydroxyl group, quinone group, lactone group, etc.) that come out when carbon black is heated at 950 ° C. for 7 minutes.

  Specific examples of the oxidation-treated carbon black include “Printex 150T” (pH 4.5, volatile content 10.0%) and “Special Black 5” (pH 3.0, volatile content 15.0%) manufactured by Degussa. ), "Special Black 4" (pH 3.0, volatile content 14.0%), "Special Black 4A" (pH 3.0, volatile content 14.0%), "MONARCH 1000" (pH 2.5) manufactured by Cabot Corporation. , Volatile content 9.5%), Cabot "MONARCH1300" (pH2.5, volatile content 9.5%), Cabot "MONARCH1400" (pH2.5, volatile content 9.0%), the same "MOGUL" -L "(pH 2.5, volatile matter 5.0%)," REGAL400R "(pH 4.0, volatile matter 3.5%) and the like.

  In the present invention, the blending amount of the above oxidized carbon black is 30 parts by weight or more and 50 parts by weight or less, as described above, but if the blending exceeds 50 parts by weight, the flexibility of the resin is lost and the elongation is increased. And physical properties such as tearing deteriorate, and cracking occurs when used as a cylindrical member. If the amount is less than 30 parts by mass, the variation in surface resistance may increase, or the surface resistivity may not be controlled in the semiconductive region. The amount of the oxidized carbon black is preferably 30 parts by mass or more and 40 parts by mass or less, and more preferably 30 parts by mass or more and 35 parts by mass or less.

When used as an intermediate transfer member, the cylindrical member of the present invention needs to have a surface resistivity of 1 × 10 ⁸ Ω / □ to 1 × 10 ¹³ Ω / □. This is because if the resistivity is lower than these values, the transfer current increases, causing transfer failure due to charge injection in the toner, and if it is high, the transfer current becomes too small to transfer the toner.
Further, since the transfer material needs to be conveyed by an electric attractive force when used as a transfer member conveying cylindrical member, the transfer material needs to be 1 × 10 ⁹ Ω / □ to 1 × 10 ¹⁴ Ω / □.

  In this way, when used as a cylindrical member for an electrostatic copying apparatus, the toner is moved by applying an electric field, so that the resistance must be uniform. If the variation becomes large, density unevenness occurs. The resistance variation width is desirably within 0.3 when a logarithmic value of a value obtained by dividing the maximum value of the surface resistivity in the belt by the minimum value is taken.

  In the cylindrical member of the present invention, since the carbon black contributing to the resistance control is contained in the specific amount, the carbon black preferably has an average particle diameter of 500 nm or less. If the particle size of the carbon black is too large, the film may become brittle and the mechanical strength may decrease.

  Here, the average particle diameter of carbon black was measured using a dynamic light scattering type measuring device PAR-III manufactured by Otsuka Electronics. The measurement conditions are: clock rate: 100 μs, accumulate time: 10 times, correlate ch: 128, temperature: 20 ° C., solvent: NMP.

The cylindrical member of the present invention has a folding endurance of 100 or more according to the MIT test. In the present invention, the measurement of the folding endurance by the MIT test method is based on JIS P8115 (2001) (“paper and board” in JIS P8115 (2001) is replaced with “polyamideimide film”). In order to set the folding endurance to 100 times or more, the oxidation-treated carbon black contained in the polyamideimide has a pH of 5 or less, a volatile content of 5% or more and 15% or less, and a content of 100 parts by mass of the polyamideimide resin. On the other hand, it may be controlled within the range of 30 parts by mass or more and 50 parts by mass or less, and the polyamideimide resin solution and the oxidized carbon black solution may be caused to collide at a pressure of 150 MPa at the time of producing the member. The greater the collision pressure, the greater the folding resistance.
In the present invention, the folding endurance is preferably 200 times or more, more preferably 1000 times or more.

In the present invention, it is preferable to contain an elastic material in order to further improve the folding resistance. By adding a flexible elastic material, the stress applied to the polyamide-imide resin can be reduced, the flexibility can be improved, and a cylindrical member having excellent shape accuracy and good folding resistance can be obtained. Such an elastic material is preferably a solvent-soluble thermoplastic elastomer. The amide solvent-soluble elastic body preferably has a 100% modulus of 40 Mpa or less, and urethane, amide or styrene thermoplastic elastomers can be used. It is preferable to use a thermoplastic elastomer. This is presumably because urethane and polyamide elastomers are uniformly distributed in the film because the composition is similar to that of polyamideimide resin. Further, if the addition amount is too large, the Young's modulus decreases, and if it is too low, improvement in flexibility is not seen. Therefore, it is preferably in the range of 5 to 50 parts by mass with respect to 100 parts by mass of the polyamideimide resin. More preferably, it is 30 parts by mass or less.
By including the elastic material as described above, the folding resistance can be greatly improved, but it is also possible to increase it to 3000 times or more.

  In the cylindrical member of the present invention, in order to satisfy the above characteristics, it is necessary to uniformly and finely disperse the oxidized carbon black in the polyamideimide resin. The manufacturing method of the cylindrical member of invention is demonstrated.

  When the cylindrical member of the present invention is mixed with a solvent-soluble polyamideimide resin and an oxidized carbon black having a pH of 5 or less and a volatile content of 5% or more and 15% or less, the pressure is 150 MPa or more. It is characterized by having a step of causing the orifice to pass and causing the orifice to collide.

  More specifically, the production method of the present invention is a step in which the oxidized carbon black-containing polyamideimide resin solution divided into two or more parts is allowed to pass through an orifice at a pressure of 150 MPa or more and collide with each other (hereinafter, “ And a step of molding a transfer member mainly composed of polyamideimide resin using the mixed oxidized carbon black-containing polyamideimide resin solution (hereinafter referred to as “molding step”). And having.

  In the mixing step, first, oxidation-treated carbon black is mixed with the polyamideimide resin solution, and the mixed solution is divided into two or more. Then, the two or more divided oxidized carbon black-containing polyamideimide resin solutions are collided with each other at a pressure of 150 MPa or more and mixed. Thus, the oxidation-treated carbon black can be finely dispersed in the polyamideimide resin solution by passing through the orifice at 150 MPa or more and colliding with each other to be mixed.

  The oxidized carbon black-containing polyamideimide resin solutions divided into two or more are collided with each other at a pressure of 150 MPa or more, and preferably collide with each other at a pressure of 180 MPa or more, more preferably 200 MPa or more. If the pressure causing the collision with each other is less than 150 MPa, the oxidized carbon black cannot be finely dispersed in the polyamideimide resin solution, and the characteristics of the transfer member described above cannot be satisfied. In practice, the upper limit of the pressure to be collided is about 300 MPa, and about 250 MPa is sufficient.

  Moreover, the collided mixed solution may be further divided into two or more, and the divided solutions may be collided with each other at a pressure of 150 MPa or more and mixed. By repeating this operation twice or more, the oxidized carbon black can be finely dispersed in the polyamideimide resin solution more efficiently.

  Such a splitting / mixing mechanism for splitting the mixed liquid into two or more is described with reference to the drawings. explain. FIG. 1 is an explanatory view for explaining a mechanism for dividing and mixing a carbon black-containing polyamideimide resin solution in the method for producing a cylindrical member of the present invention.

  The dividing / mixing mechanism shown in FIG. 1 includes two first flow path pipes 50 connected at one point from upstream to downstream, a connection pipe 52 constituting a connection part, and two or more from one end of the connection pipe 52. In this way, the solution is divided and mixed by flowing an oxidation-treated carbon black-containing polyamideimide resin solution through a flow path constituted by the second flow path pipe 54 branched into the two.

  First, each of the two first flow path pipes 50 is divided into two by flowing the oxidized carbon black-containing polyamideimide resin solution, and the flow pressure is set to 150 MPa or more, so that the connection pipes constituting the connection part are formed. In the vicinity of one end 52a of 52, the solutions collide with each other at a pressure of 150 MPa or more. Then, the mixed liquid that has collided passes through the connecting pipe 52 and flows into the second flow path pipe 54 branched into two or more, and is divided into two or more. The mixed solution divided into two or more is further allowed to flow through the first flow path pipe 50, and the mixing / division can be repeated a plurality of times.

  In such a dividing / mixing mechanism shown in FIG. 1, an oxidized carbon black-containing polyamideimide resin solution is applied to two first flow path pipes 50 connected at one point from upstream to downstream at a pressure of 150 MPa or more. It is possible to apply a collision force at a pressure of 150 MPa or more together with a shearing force to the solution, and to efficiently and uniformly disperse the oxidized carbon black at a high concentration.

Further, the mixed liquid that has collided passes through the orifice in the vicinity of one end 52a of the connecting pipe 52, but the connecting portion of the two first flow path pipes 50 (in the drawing, in the vicinity of the one end 52a of the connecting pipe 52). , i.e. the minimum cross-sectional area of the collision part two solutions collide is, 0.07 mm ² or less (preferably 0.007～0.05Mm ² or less, more preferably 0.015～0.04Mm ²⁾ with The oxidized carbon black can be finely dispersed in the polyamideimide resin solution. The reason for this is not clear, but when the solutions collide with each other at a pressure of 150 MPa or more, by reducing the area, shear force and pressure at the time of the collision can be efficiently added to the solution. It is considered that the oxidized carbon black can be finely dispersed in the solution. Here, the minimum cross-sectional area of the collision portion where the two solutions collide corresponds to the cross-sectional area of the flow channel pipe 50 in the vicinity of the inlet of the connecting pipe 52 in the drawing.

  As a collision type disperser having such a dispersion / mixing mechanism, for example, “Geanus PY” manufactured by Genus can be suitably cited. In addition, as a collision type disperser, a Sugino Machine optimizer, a Nanomizer nanomizer, and the like can be used.

  In the mixing step, the oxidized carbon black-containing polyamideimide resin solution is divided and mixed as described above, but the oxidized carbon black-containing polyamideimide resin solution dispersed by the collision type disperser is considered to be due to impact of collision. Carbon black aggregates of several tens of μm may be formed. Even if this is present, there is no major problem, but the carbon black-containing polyamic acid solution that has been divided and mixed is passed through, for example, a filter having an opening of 25 μm or less to remove carbon black aggregates, and to achieve a finer dispersion state. It becomes possible to obtain a transfer member containing carbon black.

  Next, in the molding step, the oxidized carbon black-containing polyamideimide resin solution mixed through the mixing step is applied to, for example, a cylindrical mold outer peripheral surface or inner peripheral surface to form a coating film. As this coating method, a known coating method such as a dip coating method, centrifugal molding or dipping method can be used. After coating, the solvent is dried to obtain a polyamideimide resin film.

  Finally, the polyamideimide resin coating formed on the outer peripheral surface of the mold (or other mold) is removed from the mold and cut to an appropriate width to obtain a polyamideimide resin transfer member. .

  As described above, the cylindrical member of the present invention (manufacturing method thereof) can be used for an intermediate transfer member used for an electrostatic copying type image forming apparatus such as a copying machine or a printer.

<Image forming apparatus>
The cylindrical member of the present invention is not particularly limited as long as it is a cylindrical member used in an electrostatic copying type image forming apparatus, and is a cylindrical member that conveys a transfer object, and a toner that is a first carrier. Can be used as an intermediate transfer cylindrical member or the like for transferring from the toner to the second carrier. As an example, an outline of a color image forming apparatus using an intermediate transfer member is shown below.

  FIG. 2 is a schematic diagram for explaining the main part of an image forming apparatus using a cylindrical member to which the present invention is applied as an intermediate transfer member, wherein 1 is a photosensitive drum as an image carrier, and 2 is an intermediate transfer member. 3 is a bias roll as a transfer electrode, 4 is a tray for supplying recording paper as a transfer medium, 5 is a developing device using B (black) toner, 6 is a developing device using Y (yellow) toner, 7 Is a developing device using M (magenta) toner, 8 is a developing device using C (cyan) toner, 9 is a belt cleaner, 13 is a peeling claw, 21, 23 and 24 are belt rollers, 22 is a backup roll, and 25 is a conductive roll. , 26 is an electrode roll, 31 is a cleaning blade, 41 is a bundle of recording papers, 42 is a pickup roller, and 43 is a feed roller.

In the figure, the photosensitive drum 1 rotates in the direction of arrow A, and its surface is uniformly charged by a charging device (not shown). An electrostatic latent image of the first color (for example, B) is formed on the charged photosensitive drum 1 by image writing means such as a laser writing device.
The electrostatic latent image is developed with toner by the developing device 5 to form a visualized toner image T. The toner image T reaches the primary transfer portion where the conductive roll 25 is disposed by the rotation of the photosensitive drum 1, and the toner image T is statically moved by applying an electric field having a reverse polarity from the conductive roll 25 to the toner image T. Primary transfer is performed by rotation of the transfer belt 2 in the direction of arrow B while being electrically attracted to the transfer belt 2.

  Thereafter, similarly, a second color toner image, a third color toner image, and a fourth color toner image are sequentially formed and superimposed on the transfer belt 2 to form a multiple toner image.

The multiple toner image transferred to the transfer belt 2 reaches the secondary transfer portion where the bias roll 3 is installed as the transfer belt 2 rotates.
The secondary transfer unit includes a bias roll 3 installed on the surface side of the transfer belt 2 on which the toner image is carried, a backup roll 22 arranged so as to face the bias roll from the back side of the transfer belt 2, and the backup roll 22. It consists of an electrode roll 26 that rotates in pressure contact.

The recording paper 41 is picked up one by one from the recording paper bundle stored in the recording paper tray 4 by the pickup roller 42, and is fed at a predetermined timing between the transfer belt 2 and the bias roll 3 of the secondary transfer portion by the feed roll 43. Be fed.
The toner image carried on the transfer belt 2 is transferred to the fed recording paper 41 by pressure contact conveyance by the bias roll 3 backup roll 22 and rotation of the transfer belt 2.
The recording paper 41 onto which the toner image has been transferred is peeled off from the transfer belt 2 by operating the peeling claw 13 at the retracted position until the end of the primary transfer of the final toner image, conveyed to a fixing device (not shown), and pressurized / heated. The toner image is fixed by the processing to be a permanent image.

  After the transfer of the multiple toner image to the recording paper 41 is completed, the residual toner is removed by a belt cleaner 9 provided downstream of the secondary transfer portion to prepare for the next transfer. A cleaning blade 31 made of polyurethane or the like is always attached to the bias roll 3 so as to remove foreign matters such as toner particles and paper dust adhering to the transfer.

  In the case of transfer of a single color image, the primary transferred toner image T is immediately secondarily transferred and conveyed to the fixing device. However, in the case of transfer of a multicolor image by superimposing a plurality of colors, the toner image of each color is primary transferred. The rotations of the transfer belt 2 and the photosensitive drum 1 are synchronized so that the toner images of the respective colors are not misaligned so that they are accurately matched in each part.

  In the secondary transfer section, a voltage (transfer voltage) having the same polarity as the polarity of the toner image is applied to the electrode roll 26 that is in pressure contact with the backup roll 22 that is disposed opposite to the bias roll 3 via the transfer belt 2. The image is transferred to the recording paper 41 by electrostatic repulsion.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not restrict | limited to a following example. In the following examples, “phr” means the number of parts by mass of the component added to 100 parts by mass of the resin.

[Example 1]
Solvent-soluble polyamideimide resin (Toyobo Viromax HR16NN solid content 18% by mass, solvent N-methyl-2-pyrrolidone) and carbon black (Special Black 4 Degussa pH: 3 volatile content 14%) 30 phr Then, using a high-pressure collision type disperser (manufactured by Genus), the dispersion was performed 5 times by passing through an orifice having a diameter of 0.1 mm at 150 MPa and colliding the slurry divided into two. This dispersion is applied to the outer surface of a 168 mm aluminum pipe by dip coating, dried at 150 ° C. for 30 minutes, dried in an oven at 250 ° C. for 1 hour, taken out, and the film is removed to obtain a cylindrical shape having a diameter of 168 mm and a width of 238 mm. A member was obtained.
The thickness of the obtained cylindrical member is 82 μm, the surface resistivity is 1.4 × 10 ¹² Ω / □ to 2.3 × 10 ¹² Ω / □, and the resistance variation width is 0.22 and the resistance is very uniform. It was a good belt.

  Further, the physical properties of this product were measured, and as shown in Table 1, the elongation at break was ¼ that of the additive-free material, but the physical properties were sufficiently usable as a cylindrical member.

[Example 2]
Solvent-soluble polyamideimide resin (Toyobo's Viromax HR16NN, solid content 18% by weight, solvent N-methyl-2-pyrrolidone) to carbon black (Printex V Degussa pH: 4.5, volatile content 5 wt%) 32 phr Then, using a high-pressure collision type disperser (manufactured by Genus), dispersion was performed 5 times by passing through an orifice of φ0.1 mm at 200 MPa and colliding the slurry divided into two. This dispersion is applied to the outer surface of a 168 mm aluminum pipe by dip coating, dried at 150 ° C. for 30 minutes, dried in an oven at 250 ° C. for 1 hour, taken out, and the film is removed to obtain a cylindrical shape having a diameter of 168 mm and a width of 238 mm. A member was obtained.
The thickness of the obtained cylindrical member is 79 μm, the surface resistivity is 0.95 × 10 ¹² Ω / □ to 1.4 × 10 ¹² Ω / □, and the resistance variation width is 0.16 and the resistance is very uniform. It was a good belt.

[Example 3]
35 phr of solvent-soluble polyamideimide resin (Toyobo Viromax HR16NN, solid content 18% by mass, solvent N-methyl-2-pyrrolidone) and carbon black (Special Black 4 Degussa, pH: 3, volatile content 14% by mass) Then, using a high-pressure collision type disperser (manufactured by Genus), the slurry was passed through an orifice having a diameter of 0.1 mm at 200 MPa and collided with the slurry divided into two. This dispersion was applied to the outer surface of an aluminum pipe having a diameter of 168 mm by dip coating, dried at 250 ° C., and the film was taken out to obtain a cylindrical member having a diameter of 168 mm and a width of 238 mm.
The obtained cylindrical member had a film thickness of 82 μm and a surface resistivity of 1.4 × 10 ¹² Ω / □. When a sample of a predetermined size was cut out from this belt and MIT evaluation was performed, the folding resistance was 110 times.

[Example 4]
10 phr of a thermoplastic polyurethane elastomer (BASF Elastollan 1154D) as an elastic material is sufficiently added to a solvent-soluble polyamideimide resin (Toyobo Viromax HR16NN, solid content 18% by mass, solvent N-methyl-2-pyrrolidone). Carbon black (Special Black 4 Degussa pH: 3, 14% by mass of volatile content) was added to 35 phr (the solid content of HR16NN and 1154D was set to 100) and the high-pressure collision disperser ( Dispersion was performed by passing through an orifice of φ0.1 mm at 200 Mpa and colliding with the two divided slurries. This dispersion was applied to the outer surface of an aluminum pipe having a diameter of 168 mm by dip coating, dried at 250 ° C., and the film was taken out to obtain a cylindrical member having a diameter of 168 mm and a width of 238 mm.
The obtained cylindrical member had a film thickness of 79 μm and a surface resistivity of 0.95 × 10 ¹² Ω / □. When a sample of a predetermined size was cut out from this belt and subjected to MIT evaluation, the number of folding resistances was 7200 times.

[Example 5]
Add 10 phr of a thermoplastic polyamide-based elastomer (Daicel Degussa Dyeamide 12 Elastomer E40) to a solvent-soluble polyamideimide resin (Toyobo Viromax HR16NN, solid content 18% by weight, solvent N-methyl-2-pyrrolidone) Carbon black (special black 4 Degussa pH: 3, 14% by mass of volatile content) 35 phr (solid content of HR16NN and 1154D is set to 100) is added to the one dissolved by stirring, and a high-pressure collision disperser (Genus The product was dispersed by passing it through an orifice with a diameter of 0.1 mm at 200 MPa and colliding the slurry divided into two. This dispersion was applied to the outer surface of an aluminum pipe having a diameter of 168 mm by dip coating, dried at 250 ° C., and the film was taken out to obtain a cylindrical member having a diameter of 168 mm and a width of 238 mm.
The obtained cylindrical member had a film thickness of 81 μm and a surface resistivity of 2.95 × 10 ¹² Ω / □. When a sample of a predetermined size was cut out from this belt and subjected to MIT evaluation, the number of folding resistances was 5400.

[Example 6]
Add 10 phr of a thermoplastic styrenic elastomer (DYNARON 6200P made by JSR) to solvent-soluble polyamide-imide resin (Toyobo's Viromax HR16NN, solid content 18% by weight, solvent N-methyl-2-pyrrolidone) and stir well. Add carbon black (special black 4 Degussa pH 3, volatile content 14% by mass) to 35 phr (based on solid content of HR16NN and 1154D as 100) and use high-pressure collision disperser (manufactured by Genus) Dispersion was performed by passing through an orifice having a diameter of 0.1 mm at 200 MPa and colliding with a slurry divided into two. This dispersion was applied to the outer surface of an aluminum pipe having a diameter of φ168 mm by dip coating, dried at 250 ° C., and the film was taken out to obtain a cylindrical member having a diameter of φ168 mm.
The obtained cylindrical member had a film thickness of 79 μm and a surface resistivity of 1.56 × 10 ¹² Ω / □. When a sample of a predetermined size was cut out from this belt and subjected to MIT evaluation, the number of folding resistances was 1540.

[Comparative Example 1]
39 phr of carbon black (Special Black 250 Degussa, pH 3.1, volatile matter 2.2 mass%) was added to solvent-soluble polyamide-imide resin (Toyobo Viromax HR16NN), 39 phr, and a high-pressure collision disperser (Genus) And passing through an orifice with a diameter of 0.1 mm at 200 Mpa and colliding with a slurry which was divided into two parts was dispersed five times. This dispersion was applied to the outer surface of an aluminum pipe having a diameter of 168 mm by dip coating, dried at 250 ° C., and the film was taken out to obtain a cylindrical member having a diameter of 168 mm and a width of 238 mm.
The obtained cylindrical member has a film thickness of 81 μm, a surface resistivity of 8.2 × 10 ¹² Ω / □ to 3.4 × 10 ¹³ Ω / □, and a resistance variation width of 0.62 and resistance uniformity. It was a bad belt.

[Comparative Example 2]
20 phr of Solvent Soluble Polyamideimide resin (Toyobo Viromax HR16NN, solid content 18% by mass, solvent N-methyl-2-pyrrolidone) and carbon black (Special Black 4 Degussa, pH: 3 volatile content 14% by mass) Then, using a high-pressure collision type disperser (manufactured by Genus), the dispersion was performed five times by passing through an orifice of φ0.1 mm at 100 MPa and colliding with the two divided slurries. This dispersion is applied to the outer surface of a 168 mm aluminum pipe by dip coating, dried at 150 ° C. for 30 minutes, placed in an oven at 250 ° C. for 1 hour, taken out, and the film is removed to remove a cylindrical member having a diameter of 168 mm and a width of 238 mm. Got.
The thickness of the obtained cylindrical member is 82 μm, the surface resistivity is 5.4 × 10 ¹¹ Ω / □ to 1.4 × 10 ¹¹ Ω / □, and the resistance variation width is 0.43 and the resistance is very uniform. It was a bad belt. Further, the belt surface had irregularities due to carbon black aggregates.

[Comparative Example 3]
35 phr of Solvent Soluble Polyamideimide resin (Toyobo's Viromax HR16NN, solid content 18% by mass, solvent N-methyl-2-pyrrolidone) and carbon black (Special Black 4 Degussa, pH: 3, volatile content 14% by mass) Dispersion was performed by filling a horizontal sand mill (Dynomill KDL manufactured by Dyno) with zirconia balls having a diameter of 2 mm of about 60 vol% of the inner volume and passing a stirring blade having a diameter of 90 mm at a rotation speed of 1592 rpm. This dispersion is applied to the outer surface of a 168 mm aluminum pipe by dip coating, dried at 150 ° C. for 30 minutes, placed in an oven at 250 ° C. for 1 hour, taken out, and the film is removed to remove a cylindrical member having a diameter of 168 mm and a width of 238 mm. Got.
The obtained cylindrical member has a film thickness of 82 μm and a surface resistivity of 7.8 × 10 ⁶ Ω / □ to 5.4 × 10 ⁵ Ω / □, with a resistance variation width of 0.84 and very uniform resistance. It was a bad belt.
Further, not only the surface irregularities due to the carbon black agglomerates were intense, but also the physical properties were remarkably inferior as shown in Table 1, and could not be used as a cylindrical member.

[Comparative Example 4]
Add 30 phr of carbon black (Special Black 4 Degussa pH: 3 volatile matter 14 mass%) to polyimide resin (Ube Industries U varnish S solid content ratio 18 mass% solvent N-methyl-2-pyrrolidone), high pressure collision Using a type disperser (product of Genus), dispersion was performed 5 times by passing through an orifice of φ0.1 mm at 200 MPa and colliding with a slurry divided in two. This dispersion is applied to the outer surface of a 168 mm aluminum pipe by dip coating, dried at 150 ° C. for 30 minutes, placed in an oven at 340 ° C. for 3 hours, taken out, and the film is removed to remove a cylindrical member having a diameter of 168 mm and a width of 238 mm. Got.
Although the obtained cylindrical member had a film thickness of 82 μm, the surface resistivity was 7.8 × 10 ³ Ω / □, and the belt could not be used as a cylindrical member for electrostatic copying.

<Evaluation>
The following evaluation tests were performed on the cylindrical members of Examples 1 to 6 and Comparative Examples 1 to 4 manufactured as described above. The results are shown in Table 1.

(Mechanical strength test)
As a mechanical strength test, an autograph (manufactured by Toyo Seiki Seisakusho Co., Ltd., V1-C) is used, and a sample cut out from a cylindrical member to a size of 5 mm × 50 mm is held so that the distance between chucks is 40 mm. The Young's modulus, tensile strength, and elongation at break were measured at a normal temperature and a tensile speed of 20 mm / min.
The Young's modulus was determined from the amount of elongation at 1% elongation and the tension.

(Surface resistivity)
A measuring device having an inner cylinder φ16 mm and an outer cylinder φ30 mm × φ40 mm with a double cylinder probe and an insulating lower surface was used. The amount of current flowing through the outer cylinder when 10 V was applied to the inner cylinder of this apparatus (10 seconds after voltage application) was measured, and the surface resistivity of the film was determined by calculation.
The variation width of the surface resistivity was a common logarithm value obtained by dividing the maximum value of the surface resistivity of each cylindrical member by the minimum value. A belt having a small variation width is desired along with the increase in speed and image quality of the electrostatic copying system, but it can be said that there is no practical problem if it is 0.3 or less.

(Number of folding times)
The number of folding endurances measured by the MIT test method was measured using an MIT test machine shown in FIG. FIG. 3 is a schematic configuration diagram for explaining the MIT testing machine. The MIT testing machine shown in FIG. 3 has a bending device 66 having a radius of curvature of 0.38 mm, which is attached to the bending device attachment surface 64 and has a radius of curvature of 0.38 mm for sandwiching the test piece 62, and a load attached to the plunger 68. It consists of a gripping tool 70 for hanging.

  The procedure for measuring the folding endurance by the MIT test method is as follows. One of the test pieces 62 cut out to a size of 20 mm × 250 mm is sandwiched by a bending device 66. Further, the other one of the test pieces 62 is sandwiched by the gripping tool 70 and a load of 10 N is applied to the test piece 62. Next, the bending device 66 is rotated at an angle of 135 ± 2 ° at a speed of 175 ± 10 times per minute, and the loaded test piece 62 is repeatedly bent at the curvature surface of the bending device 66 to cause stress. To break. The number of times of bending N until breakage (average value of five measurements) was defined as the number of folding times.

(Evaluation of transfer image quality)
The obtained cylindrical member was attached as an intermediate transfer belt 2 to an image forming apparatus having the same configuration as the image forming apparatus shown in FIG. Using such an image forming apparatus, the transfer image quality by primary transfer and secondary transfer was evaluated as follows. The recording paper 41 used here is Fuji Xerox Office Supply Co., Ltd. full color copier paper J paper. As the toner, a spherical toner having a shape factor (SF) of 125 and a volume average particle diameter of 5.5 μm was used.
The print samples were evaluated for density uniformity using a halftone image having 20% of magenta and cyan as an image pattern.
-Transfer image quality after continuous 10,000 sheets printing-
The evaluation criteria for the transfer image quality are as follows. The evaluation results are shown in Table 1 below.
○: There is no density unevenness and no problem in image quality.
X: There is uneven density and there is a problem in image quality.

From Table 1, as shown in Examples 1 to 6, by adding a large amount of carbon black having a pH of 5 or less and a volatile content of 5% or more and 15% or less, such as 30 phr or more, uneven distribution of carbon black can be eliminated and resistance. A cylindrical member with good uniformity and good productivity was obtained. As a result, a very good cylindrical member having a variation width of the surface resistivity of 0.3 or less could be obtained.
Further, from the result of Comparative Example 3, it can be seen that in order to obtain a blending ratio of 30 phr or more, it is necessary to use a high-pressure collision type dispersion device that causes the micro orifice to pass through and collide with a pressure of 150 MPa or more.
Furthermore, in Comparative Example 4 in which a cylindrical member was produced in the same manner as in the example except that the polyamideimide resin was changed to a polyimide resin, the polyamideimide resin was not usable because of the numerical value of the surface resistivity. It is presumed that the dispersibility with respect to carbon black was better than that of polyimide resin, and the carbon black could be sufficiently filled.
Furthermore, although Examples 4-6 are the examples which contained the elastic material, when an elastic material is contained, it turns out that the frequency | count of bending of 3000 times or more can be achieved.

It is explanatory drawing for demonstrating the division | segmentation and mixing mechanism of the oxidation process carbon black containing polyamide-imide resin solution in the manufacturing method of the cylindrical member of this invention. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention. It is a schematic block diagram for demonstrating a MIT testing machine.

Explanation of symbols

1 Photosensitive drum (image carrier)
2 Intermediate transfer belt (intermediate transfer member)
DESCRIPTION OF SYMBOLS 3 Bias roll 4 Paper tray 5 Black developing device 6 Yellow developing device 7 Magenta developing device 8 Cyan developing device 9 Intermediate transfer body cleaning device 13 Peeling claw 21 Belt roll 22 Backup roll 23 Belt roll 24 Belt roll 25 Conductive roll 26 Electrode roll 31 Cleaning Blade 41 Recording Paper 42 Pickup Roll 43 Feed Roll

Claims (6)

The solvent solution containing solvent-soluble polyamideimide resin is mixed with oxidized carbon black having a pH of 5 or less and a volatile content of 5% or more and 15% or less, and then containing the oxidized carbon black. Is divided into two or more, and passes through the orifice at a pressure of 150 MPa or more, and is manufactured to include a step of colliding with each other,
The content of the oxidized carbon black is not more than 50 parts by 30 weight parts or more with respect to the solvent-soluble polyamide-imide resin 100 parts by weight, folding number by MIT test method performed under a load of 10N A cylindrical member characterized by being 100 times or more. The cylindrical member according to claim 1, wherein the in-plane variation width of the logarithmic value of the surface resistivity is 0.3 or less. The cylindrical member according to claim 1 or 2 , further comprising an elastic material. The cylindrical member according to claim 3 , wherein the elastic material is a solvent-soluble thermoplastic elastomer. Image forming apparatus comprising a cylindrical member according to any one of claims 1 to 4. In a solvent solution containing a solvent-soluble polyamideimide resin , an oxidized carbon black having a pH of 5 or less and a volatile content of 5% or more and 15% or less is 30 parts by mass or more and 50 parts by mass with respect to 100 parts by mass of the polyamideimide resin. A cylindrical shape characterized by having a step of mixing a part or less, and then dividing the solvent solution containing the oxidized carbon black into two or more and passing the orifices at a pressure of 150 MPa or more and causing them to collide with each other. Manufacturing method of member.

Images