JP2016169346A - Resin composition, and member for image formation and image forming apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition in which variations in surface resistivity are reduced and occurrence of bleeding is suppressed.SOLUTION: A resin composition contains a first thermoplastic resin, a second thermoplastic resin, and a conductive filler; and has such a sea-island structure that the second thermoplastic resin becomes an island in a continuous phase of the first thermoplastic resin. In the cross section of the resin composition, a ratio of the area of the conductive filler existing in the second thermoplastic resin to the total sum of the areas of the conductive fillers existing in both the first thermoplastic resin and the second thermoplastic resin is 40% to 75%. A melting point of the second thermoplastic resin is 170°C or higher and 220°C or lower.SELECTED DRAWING: None

Description

  The present invention relates to a resin composition, and an image forming member and an image forming apparatus using the resin composition.

  Various resin compositions are required for an electrophotographic image forming apparatus, and examples thereof include a seamless belt formed from the resin composition as an image forming member. The seamless belt is used, for example, as an intermediate transfer belt, a conveyance belt, a fixing belt, and the like. Among these, the seamless belt is preferably used as the intermediate transfer belt.

  In the intermediate transfer belt, in order to stabilize the image quality of the image forming apparatus, stable mechanical characteristics and electrical characteristics are required over a long period of time. As the electrical characteristics, for example, it is required to reduce variations in the surface resistivity so that the surface resistivity of the intermediate transfer belt is within a range where semiconductivity can be obtained. When the variation in the surface resistivity is large, the surface potential of the intermediate transfer belt is not uniform, and there is a problem that image quality is deteriorated due to occurrence of a portion where the toner image is not partially transferred. In particular, the seamless belt produced by extrusion molding of a thermoplastic resin containing a conductive filler can be continuously produced and is advantageous for cost reduction. However, the conductive filler is agglomerated by heat treatment in the molding process. In some cases, the variation in the surface resistivity is larger than that before the heat treatment.

  In order to solve this problem, for example, a seamless belt is manufactured by installing a temperature-controlled mandrel inside an annular die of an extruder, extruding the thermoplastic resin into a tube shape, and cutting it into a ring shape. A method of manufacturing a seamless belt, wherein a temperature-controlled gas is blown to the outer peripheral surface of the annular die in the vicinity of the upstream side of the mandrel in order to bring the outer peripheral surface temperature of the annular die closer to the temperature of the mandrel It has been proposed (Patent Document 1).

However, the above-described manufacturing method requires a device for spraying a temperature-controlled gas, and there is a problem that the manufacturing process becomes complicated.
On the other hand, when the intermediate transfer belt made of the resin composition is provided in the image forming apparatus, a bleed generated due to condensation of the intermediate transfer belt is generated in the image carrier, particularly in a high temperature and high humidity environment. It will adhere to the surface. Then, a portion where the electrostatic latent image of the image carrier is not developed into the toner image is generated, and the image quality may be deteriorated. Therefore, improvement of bleeding of the resin composition is desired.
Then, an object of this invention is to provide the resin composition which suppressed generation | occurrence | production of bleeding while reducing the dispersion | variation in surface resistivity.

The resin composition of the present invention as a means for solving the problems includes a first thermoplastic resin, a second thermoplastic resin, and a conductive filler, and is in a continuous phase of the first thermoplastic resin. A resin composition having a sea-island structure in which the second thermoplastic resin has an island shape,
In the cross section of the resin composition, the total area of the conductive filler existing in both the first thermoplastic resin and the second thermoplastic resin is present in the second thermoplastic resin. The area ratio of the conductive filler is 40% to 75%,
The melting point of the second thermoplastic resin is 170 ° C. or higher and 220 ° C. or higher.

  According to the present invention, it is possible to provide a resin composition in which variation in surface resistivity is reduced and generation of bleeding is suppressed.

FIG. 1 is a schematic sectional view showing an example of the image forming apparatus of the present invention. FIG. 2 is a schematic sectional view showing an example of an image forming unit having the image carrier in FIG. FIG. 3 is an explanatory diagram showing the dependence of the surface resistivity on the molding temperature in the intermediate transfer belt as the image forming member of the present invention. FIG. 4 is an explanatory view showing an example of an extrusion molding apparatus.

(Resin composition)
The resin composition of the present invention contains at least two types of thermoplastic resins and a conductive filler, and further contains other components as necessary.
The resin composition has a structure in which other thermoplastic resins are dispersed in one thermoplastic resin by using a combination in which the two or more types of thermoplastic resins are hardly compatible with each other. Therefore, when the cross-sectional image of the resin composition is confirmed with a scanning electron microscope or the like, when the continuous phase of the one thermoplastic resin is expressed as “sea”, the other thermoplastic resin is contained in the “sea”. It shows the sea-island structure that becomes “island”. In the resin composition showing the sea-island structure, it is preferable that the conductive filler is unevenly distributed in the other island-shaped thermoplastic resin.

The resin composition is not particularly limited as long as it is semiconductive, and can be appropriately selected according to the purpose. The semiconductivity means that the surface resistivity is in the range of 10 ⁷ Ω / □ to 10 ¹³ Ω / □ when measured by applying 500 V for 10 seconds with a resistivity meter, for example. .

<Thermoplastic resin>
The thermoplastic resin is not particularly limited as long as it is a combination of the two or more thermoplastic resins that are hardly compatible, and can be appropriately selected according to the purpose. Of the two or more types of thermoplastic resins, the one thermoplastic resin that forms the “sea” is the first thermoplastic resin, and the other thermoplastic resin that forms the “island” is the second thermoplastic resin. Examples of the thermoplastic resins that are difficult to be compatible will be described below.

<< first thermoplastic resin >>
Examples of the first thermoplastic resin include polyvinylidene fluoride (PVDF) resin, polyethylene resin, polypropylene resin, polystyrene resin, thermoplastic polyamide (PA) resin, acrylonitrile-butadiene-styrene (ABS) resin, and thermoplastic polyacetal. (POM) resin, thermoplastic polyarylate (PAR) resin, thermoplastic polycarbonate (PC) resin, thermoplastic urethane resin, polyethylene naphthalate (PEN) resin, polybutylene naphthalate (PBN) resin, polyalkylene terephthalate resin, polyester Based resins and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, the said polyvinylidene fluoride resin is preferable at the point which has a high elasticity modulus, folding resistance, and a flame retardance.

-Polyvinylidene fluoride resin-
Examples of the polyvinylidene fluoride resin include homopolymers (polyvinylidene fluoride), vinylidene fluoride-hexafluoropropylene copolymers (copolymers of VDF and HFP), and the like.
The polyvinylidene fluoride resin is not particularly limited and can be appropriately selected depending on the purpose, and is produced by an emulsion polymerization method or a suspension polymerization method.
Examples of the homopolymer include Kynar (registered trademark) 710, 711, 720, 721, 740, 741, 760, 761, 761A, HSV900, 466, 461, 301F, 370, 9000HD, 6000HD, 1000HD (both Arkema), Solef (registered trademark) Visc. 8, 10, 12, 15, 20 (all are manufactured by Solvay). These may be used individually by 1 type and may use 2 or more types together.
Examples of the vinylidene fluoride-hexafluoropropylene copolymer include Kynar (registered trademark) Flex 2850-00, 2851-00, 2800-00, 2801-00, 2800-20, 2821-00, 2750-01, and 2751. -00, 2500-20, 2501-20, 3120-50 (all manufactured by Arkema), Solef (registered trademark) flex Visc. 8, 10 and SuperFlex Visc8 (manufactured by Solvay). These may be used individually by 1 type and may use 2 or more types together.

<< second thermoplastic resin >>
The second thermoplastic resin is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably a resin having a polyethylene oxide unit, such as a polyamide / polyether copolymer or a polyether ester amide. Resin, ethylene oxide-epichlorohydrin resin, polyether ester resin and the like. In addition, you may make these resin contain an organic salt and a metal salt in order to improve electroconductivity.

The unreacted polyethylene oxide unit, the organic salt, the metal salt, and the like are easily soluble in water, and therefore the bleed is generated particularly in a high-temperature and high-humidity environment where condensation occurs on the surface of the resin composition. Likely to happen.
For example, when the intermediate transfer belt is formed using the resin composition that is semiconductive, if the bleed occurs on the surface of the intermediate transfer belt, the surface of the image carrier that contacts the intermediate transfer belt Bleed adheres. Then, the portion attached to the surface of the image carrier has conductivity, and it is difficult to form an electrostatic latent image, so that the toner does not adhere to the surface of the image carrier and the image is whitened. Quality anomalies may occur.
For this reason, it is preferable that the second thermoplastic resin in the resin composition of the present invention has the polyamide / polyether copolymer from the viewpoint of suppressing generation of the bleed.

-Bleed rate in distilled water-
There is no restriction | limiting in particular as a bleed rate to the distilled water of a said 2nd thermoplastic resin, Although it can select suitably according to the objective, It is preferable that it is 4 mass% or less. When the bleed rate is within a preferable range, for example, when the intermediate transfer belt is formed using the resin composition, the influence of the bleed on the image carrier that contacts the intermediate transfer belt is reduced. This is advantageous in that the image quality can be maintained.

As a method for measuring the bleed rate, for example, it can be measured by the following procedure.
First, the second thermoplastic resin (mass A) and distilled water (mass B) are put in a glass container and hermetically sealed, and the glass container is dried by a 45 ° C. dryer for 1 hour. The dried glass container is vibrated for 40 minutes with an ultrasonic vibration generator, and the glass container is again dried with a dryer at 45 ° C. for 8 hours. The distilled water extract (mass D) in the glass container taken out from the dryer is put into a glass petri dish (mass C).
Next, in order to evaporate the water of the distilled water extract to precipitate a solid content, the petri dish was dried for 3 hours with a dryer at 105 ° C., then taken out of the dryer and air-cooled for 1 hour, The petri dish (mass E) is measured. The masses A to E were measured with a precision balance.
And the measured mass A-mass E are substituted into the following [Formula 1], and the bleed rate to the distilled water is calculated.

[Formula 1]
(Bleed rate in distilled water (%)) = ((EC) / ((A / B) × D)) × 100

-Content ratio to the entire resin composition-
There is no restriction | limiting in particular in the content rate of the said 2nd thermoplastic resin with respect to the said whole resin composition, Although it can select suitably according to the objective, 2 mass% or more and 7 mass% or less are preferable. When the content is within a preferable range, the occurrence of bleeding due to the second thermoplastic resin can be suppressed, and the conductive filler is not dispersed throughout the resin composition. This is advantageous in that it can be made smaller.
Note that, if the content rate is decreased, the variation in the surface resistivity is increased, but the bleed rate is reduced.If the content rate is increased, the variation in the surface resistivity is decreased, but the bleed rate is increased. The content rate is determined by a balance between the variation in the surface resistivity and the bleed rate.

-Conductive filler content relative to the entire resin composition-
There is no restriction | limiting in particular as an electroconductive filler content rate with respect to the said whole resin composition in a said 2nd thermoplastic resin, Although it can select suitably according to the objective, 40%-75% are preferable, 50%- 70% is more preferable. When the conductive filler content is within a preferable range, it is advantageous in that variation in the surface resistivity can be reduced.
The conductive filler content is obtained by taking a cross-section of the resin composition with a scanning electron microscope (SEM), the total area of the conductive filler contained in the second thermoplastic resin, and the first It can be determined by calculating the ratio with the total area of the conductive filler contained in the thermoplastic resin.

-Melting point-
The melting point is not particularly limited as long as it is higher than the melting point of the first thermoplastic resin, and can be appropriately selected according to the purpose, but is preferably 170 ° C. or higher and 220 ° C. or higher, and 200 ° C. or higher and 220 ° C. or higher. More preferred. When the melting point is within a preferable range, in the case of molding using the resin composition, the conductive filler unevenly distributed in the second thermoplastic resin aggregates even when the heating temperature in the molding process is increased. This makes it difficult to reduce variations in the surface resistivity.
The melting point can be measured, for example, using a differential scanning calorimeter DSC (TA Instruments, Q2000).

-Surface resistivity-
The surface resistivity of the second thermoplastic resin is preferably 5 × 10 ⁷ Ω / □ or less. When the surface specific resistivity is within a preferable range, the conductive filler content can be reduced, and aggregation of the conductive filler can be suppressed, which is advantageous in that variation in the surface resistivity can be reduced. In addition, when the said bleed rate calculated | required by said [Formula 1] is the same, the one where the said surface specific resistivity is low is preferable at the point which is easy to make the dispersion | variation in the said surface resistivity and the said bleed rate compatible.
The surface specific resistivity can be measured in accordance with, for example, ASTM D257.

<Conductive filler>
There is no restriction | limiting in particular as said electroconductive filler, According to the objective, it can select suitably, For example, carbon black, a carbon nanotube, a metal oxide, an ionic conductive agent etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, the carbon black is preferable.

  Examples of the carbon black include channel black, ketjen black, furnace black, acetylene black, thermal black, gas black, and graphite. Moreover, it may be oxidized for various uses, or may be basic or acidic by applying a surface treatment by applying a compound such as a coupling agent having a functional group. Among these, the acetylene black is preferable from the viewpoint of dispersibility.

  Examples of the metal oxide include zinc oxide, tin oxide, titanium oxide, zirconium oxide, aluminum oxide, silicon oxide, and surface treated products thereof.

  Examples of the ionic conductive agent include tetraalkyl ammonium salt, trialkyl benzyl ammonium salt, alkyl sulfonate, alkyl benzene sulfonate, alkyl sulfate, glycerin fatty acid ester, sorbitan fatty acid ester, polyoxyethylene alkylamine, polyoxyethylene. Examples include fatty alcohol esters, alkyl betaines, and lithium perchlorates.

-DBP oil absorption-
As the DBP oil ^absorption, 200 cm 3/100 g or less is preferable. When the DBP oil absorption is within a preferable range, the dispersibility of the conductive filler is increased, and the conductive filler is less likely to aggregate due to the heat treatment of the molding step, so that variation in the surface resistivity can be reduced. Is advantageous.
The DBP oil absorption is the amount of DBP (dibutyl phthalate) absorbed by 100 g of the conductive filler, and can be measured according to JIS K6221.

-Average primary particle size-
The average primary particle size is preferably 10 nm or more and 40 nm or less. When the average primary particle size is within a preferable range, the dispersibility of the conductive filler in the resin composition is increased, and the conductive filler is less likely to aggregate. This is advantageous.
The average primary particle size can be determined, for example, as follows.
First, the conductive filler (20% by mass solid content) after the oxidation treatment was diluted to 0.1% by mass with water, and this diluted solution was sprayed onto the mesh with a collodion film and dried. Arithmetic mean diameter (number average) obtained from the distribution of the diameters of circles (equal area circle diameters) having the same area as the projected area of each primary particle extracted by photographing this with a transmission electron microscope and digitizing the photograph Value) as the average primary particle size.

-PH-
The pH is preferably 9 or more. When the pH is within a preferable range, the dispersibility of the conductive filler in the resin is increased, and the conductive filler is less likely to aggregate, which is advantageous in that variation in the surface resistivity can be reduced.
The pH can be measured from a mixed solution of the conductive filler and distilled water using a glass electrode pH meter.

<Other ingredients>
The other components are not particularly limited and may be appropriately selected depending on the purpose. For example, lubricants, electrical resistance adjusters, antioxidants, reinforcing agents, fillers, vulcanization accelerators, extenders, Various pigments, ultraviolet absorbers, antistatic agents, dispersants, neutralizers and the like can be mentioned.

<Method for producing resin composition>
The method for producing the resin composition is not particularly limited and may be appropriately selected depending on the purpose, and includes a melt-kneading step of melt-kneading the thermoplastic resin and the conductive filler. This is preferable in that the conductive filler is dispersed in the thermoplastic resin.

<< Melt kneading process >>
There is no restriction | limiting in particular as said melt-kneading process, According to the objective, it can select suitably, It can carry out suitably using a melt-kneading apparatus.
The melt kneading apparatus is not particularly limited as long as it can be melt kneaded with the thermoplastic resin and the conductive filler, and can be appropriately selected according to the purpose. For example, a single screw extruder, a twin screw extruder, and the like. And kneaders such as a Banbury mixer, a roll and a kneader. Specifically, KTK type twin screw extruder manufactured by Kobe Steel, TEM type twin screw extruder manufactured by Toshiba Machine Co., Ltd., TEX type twin screw extruder manufactured by Nippon Steel Co., Ltd., and PCM type twin screw extruder manufactured by Ikekai Tekko Co., Ltd. KEX type twin screw extruder manufactured by Kurimoto Iron Works Co., Ltd., and heat kneaders such as Bush Co. kneader which is a continuous single screw kneader.

  As a melting temperature in the said melt-kneading process, 180 to 240 degreeC is preferable and 180 to 220 degreeC is more preferable. When the melting temperature is within a preferable range, it is advantageous in terms of dispersibility of carbon black.

In addition, as described above, in the resin composition of the present invention, it is preferable that the conductive filler content of the second thermoplastic resin with respect to the entire resin composition is 40% to 75%.
However, the dispersibility of the conductive filler may differ between the first thermoplastic resin and the second thermoplastic resin, and the first thermoplastic resin, the second thermoplastic resin, and the If the conductive filler is added at a time, the conductive filler may be unevenly distributed in any of the thermoplastic resins, and thus the conductive filler content may not be 40% to 75%.
In such a case, after melt-kneading with the said conductive filler separately with a twin-screw extruder etc. for every kind of thermoplastic resin previously, after processing into a pellet with a pelletizer, you may mix together. For example, a pellet A is prepared by melting and kneading the first thermoplastic resin and the conductive filler, and a pellet B is prepared by melting and kneading the second thermoplastic resin and the conductive filler, and finally the pellet. The resin composition may be prepared by melt-kneading A and pellet B.

<Resin molding>
There is no restriction | limiting in particular except the resin molding used by this invention shape | molding the said resin composition of this invention, According to the objective, it can select suitably.

<Molding method of resin molding>
There is no restriction | limiting in particular as a shaping | molding method of the said resin molding, Although it can select suitably according to the objective, It is preferable to include the shaping | molding process of shape | molding to the said resin molding, heating the said resin composition. .

<< Molding process >>
There is no restriction | limiting in particular as said shaping | molding process, According to the objective, it can select suitably, For example, film shaping | molding, extrusion molding, injection molding, blow molding, compression molding, transfer molding, calendar molding, thermoforming, fluid molding And laminate molding. Among these, when the resin molded body is used for an image output device such as a copying machine or a printer, or an electrical or electronic device such as a home appliance, any one selected from film molding, extrusion molding, and injection molding Is preferred.
Moreover, the said shaping | molding process can be performed suitably using a shaping | molding apparatus.
There is no restriction | limiting in particular as said shaping | molding apparatus, According to the objective, it can select suitably. For example, an extrusion molding apparatus may be used to mold a seamless belt as an image forming member provided in the image forming apparatus.

  The heating temperature in the molding step is preferably 180 ° C to 240 ° C, more preferably 180 ° C to 220 ° C. When the heating temperature is within a preferable range, it is advantageous from the viewpoint of moldability.

(Image forming member)
The image forming member of the present invention is not particularly limited and may be appropriately selected according to the purpose. For example, an intermediate transfer belt as an intermediate transfer member, a conveyance belt as a conveyance unit, and a transfer belt as a transfer unit The fixing belt is used as a fixing belt, and the developing belt is used as a developing means. However, the fixing belt is preferably used as the intermediate transfer belt.
Hereinafter, the intermediate transfer belt molded using the resin composition will be described.

-Average thickness-
There is no restriction | limiting in particular as average thickness of the said intermediate transfer belt, Although it can select suitably according to the objective, 30 micrometers-200 micrometers are preferable, and 50 micrometers-150 micrometers are more preferable. When the average thickness is less than 30 μm, the strength decreases, and the intermediate transfer belt may be easily torn. When the average thickness exceeds 200 μm, flexibility is lost and belt running performance is lowered, and the belt is cracked. May be easier.
The average thickness of the intermediate transfer belt can be measured using, for example, a contact type (pointer type) or eddy current type film thickness meter, for example, an electronic micrometer (manufactured by Anritsu).

−Surface resistivity−
The surface resistivity is not particularly limited and may be appropriately selected depending on the purpose. However, the surface resistivity is 1 × 10 ⁸ Ω / □ to 1 × 10 ¹¹ Ω / □ (however, the applied voltage during measurement is 10 V to 500 V). Between) is preferred.
The surface resistivity can be measured, for example, using a resistivity meter (manufactured by Mitsubishi Chemical Analytech, Hiresta UX MCP-HT450, Hiresta URS probe) at a temperature of 20 ° C. ± 3 ° C. and a relative humidity of 50% ± 10%. Can be measured.

-Variation in surface resistivity-
The variation in the surface resistivity is not particularly limited as long as the intermediate transfer belt is semiconductive, and can be appropriately selected according to the purpose. However, the variation in the surface resistivity is 1 when plotted on a common logarithmic scale. When the interval of × 10 ¹ is 1, it is preferably less than 1. When the variation in the surface resistivity is within a preferable range, it is advantageous in that the primary transfer and the secondary transfer are performed even in the portion where the surface resistivity is high, and the image quality can be maintained.

(Image forming apparatus and image forming method)
The image forming apparatus of the present invention has at least an electrostatic latent image carrier (hereinafter sometimes referred to as “image carrier”), an electrostatic latent image forming unit, a developing unit, and a transfer unit. In addition, other means are provided as necessary.
An image forming apparatus according to the present invention includes the image forming member according to the present invention.
The image forming member is an intermediate transfer belt, and the transfer unit includes the intermediate transfer belt.
The image forming method of the present invention includes at least an electrostatic latent image forming step, a developing step, and a transfer step, and further includes other steps as necessary.
The image forming method can be preferably performed by the image forming apparatus, the electrostatic latent image forming step can be preferably performed by the electrostatic latent image forming unit, and the developing step can be performed by the developing unit. The other steps can be preferably performed by the other means.

<Electrostatic latent image carrier>
The material, structure and size of the electrostatic latent image carrier are not particularly limited and can be appropriately selected from known materials. Examples of the material include inorganic image carriers such as amorphous silicon and selenium. Body, organic image carriers such as polysilane, phthalopolymethine, and the like. Among these, amorphous silicon is preferable in terms of long life.

  As the amorphous silicon image carrier, for example, a support is heated to 50 ° C. to 400 ° C., and a vacuum deposition method, a sputtering method, an ion plating method, thermal CVD (chemical vapor deposition, Chemical Vapor) is formed on the support. An image carrier having a photoconductive layer made of a-Si can be used by a film formation method such as a deposition method, a photo CVD method, or a plasma CVD method. Among these, a plasma CVD method, that is, a method in which a source gas is decomposed by direct current, high frequency or microwave glow discharge to form an a-Si deposited film on a support is preferable.

  There is no restriction | limiting in particular as a shape of the said electrostatic latent image carrier, Although it can select suitably according to the objective, A cylindrical shape is preferable. The outer diameter of the cylindrical electrostatic latent image carrier is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 3 mm to 100 mm, more preferably 5 mm to 50 mm, and more preferably 10 mm to 30 mm. Particularly preferred.

<Electrostatic latent image forming means and electrostatic latent image forming step>
The electrostatic latent image forming means is not particularly limited as long as it is a means for forming an electrostatic latent image on the electrostatic latent image carrier, and can be appropriately selected according to the purpose. Examples thereof include at least a charging member that charges the surface of the electrostatic latent image carrier and an exposure member that exposes the surface of the electrostatic latent image carrier imagewise.
The electrostatic latent image forming step is not particularly limited as long as it is a step of forming an electrostatic latent image on the electrostatic latent image carrier, and can be appropriately selected according to the purpose. After the surface of the electrostatic latent image carrier is charged, the imagewise exposure can be performed, and the electrostatic latent image forming unit can be used.

-Charging member and charging-
The charging member is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charger including a conductive or semiconductive roller, brush, film, rubber blade, etc. And non-contact chargers utilizing corona discharge such as corotron and scorotron.
The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charging member.

The shape of the charging member may take any form such as a magnetic brush or a fur brush in addition to a roller, and can be selected according to the specifications and form of the image forming apparatus.
When the magnetic brush is used as the charging member, as the magnetic brush, for example, various ferrite particles such as Zn-Cu ferrite are used as the charging member, and a nonmagnetic conductive sleeve for supporting the ferrite particle is included in the charging member. It consists of a magnet roll.
When the fur brush is used as the charging member, as the material of the fur brush, for example, a fur conductively treated with carbon, copper sulfide, metal, or metal oxide is used, and this is subjected to metal or other conductive treatment. A charging member can be obtained by winding or sticking to a cored bar.
The charging member is not limited to the contact-type charging member, but it is preferable to use a contact-type charging member because an image forming apparatus in which ozone generated from the charging member is reduced can be obtained.

-Exposure member and exposure-
The exposure member is not particularly limited and may be appropriately selected depending on the purpose, as long as the surface of the electrostatic latent image carrier charged by the charging member can be exposed like an image to be formed. Examples thereof include various exposure members such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system.
There is no restriction | limiting in particular as a light source used for the said exposure member, According to the objective, it can select suitably, For example, a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser General light emitting materials such as (LD) and electroluminescence (EL).
In addition, various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.
The exposure can be performed, for example, by exposing the surface of the latent electrostatic image bearing member imagewise using the exposure member.
In the present invention, a back light system in which imagewise exposure is performed from the back side of the electrostatic latent image carrier may be employed.

<Developing means and development process>
The developing unit is not particularly limited as long as it is a developing unit equipped with toner that develops the electrostatic latent image formed on the electrostatic latent image carrier to form a toner image, depending on the purpose. It can be selected appropriately.
The development step is not particularly limited as long as it is a step of developing the electrostatic latent image formed on the electrostatic latent image carrier into a toner image, and can be appropriately selected according to the purpose. , Can be performed by the developing means.

The developing means may be of a dry development type or a wet development type. Further, it may be a single color developing means or a multicolor developing means.
The developing means includes a stirrer for charging the toner by frictional stirring and a magnetic field generating means fixed inside, and a developer carrying that can carry and rotate the developer containing the toner on the surface. A developing device having a body is preferred.
In the developing means, for example, the toner and the carrier are mixed and stirred, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state, thereby forming a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrostatic latent image carrier, a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrostatically attracted by the static force. It moves to the surface of the electrostatic latent image carrier. As a result, the electrostatic latent image on the surface of the electrostatic latent image carrier is developed into the toner image.

<Transfer means and transfer process>
The transfer unit is not particularly limited as long as it is a unit that transfers a toner image to a recording medium, and can be appropriately selected according to the purpose. However, the toner image is transferred onto an intermediate transfer member and combined transfer is performed. An embodiment having a primary transfer unit for forming an image and a secondary transfer unit for transferring the composite transfer image onto a recording medium is preferable.
The transfer step is not particularly limited as long as it is a step of transferring the toner image to a recording medium, and can be appropriately selected according to the purpose. A mode in which the toner image is firstly transferred and then the toner image is secondarily transferred onto the recording medium is preferable.
The transfer step can be performed, for example, by charging the toner image on the image carrier using a transfer charger, and can be performed by the transfer unit.
Here, when the image to be secondarily transferred onto the recording medium is a color image composed of a plurality of colors of toner, the intermediate transfer is performed by sequentially superimposing the toner of each color on the intermediate transfer member by the transfer means. An image can be formed on the body, and the image on the intermediate transfer body can be secondarily transferred collectively onto the recording medium by the intermediate transfer unit.
The intermediate transfer member is not particularly limited and can be appropriately selected from known transfer members according to the purpose. For example, an intermediate transfer belt molded using the resin composition of the present invention is preferable. .

The transfer unit (the primary transfer unit and the secondary transfer unit) preferably includes at least a transfer unit that peels and charges the toner image developed on the image carrier toward the recording medium. Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and can be appropriately selected according to the purpose. A PET base or the like can also be used.

<Other means and other processes>
Examples of the other means include a fixing means, a cleaning means, a static elimination means, a recycling means, and a control means.
Examples of the other processes include a fixing process, a cleaning process, a static elimination process, a recycling process, and a control process.

-Fixing means and fixing process-
The fixing unit is not particularly limited as long as it is a unit that fixes the transferred image transferred to the recording medium, and can be appropriately selected according to the purpose. However, a known heating and pressing member is preferable. Examples of the heating and pressing member include a combination of a heating roller and a pressing roller, and a combination of a heating roller, a pressing roller, and an endless belt.
The fixing step is not particularly limited as long as it is a step of fixing the toner image transferred to the recording medium, and can be appropriately selected according to the purpose. For example, each color toner is applied to the recording medium. It may be performed each time the image is transferred, or may be performed simultaneously at the same time in a state where the toners of the respective colors are stacked.
The fixing step can be performed by the fixing unit.
The heating in the heating and pressing member is usually preferably 80 ° C to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing unit depending on the purpose.

The surface pressure in the fixing step is not particularly limited and may be appropriately selected depending on the intended ^purpose, is preferably ^{10N / cm 2 ~80N / cm 2} .

-Cleaning means and cleaning process-
The cleaning means is not particularly limited as long as it can remove the toner remaining on the image carrier, and can be appropriately selected according to the purpose. For example, a magnetic brush cleaner or an electrostatic brush cleaner , Magnetic roller cleaner, blade cleaner, brush cleaner, web cleaner and the like.
The cleaning step is not particularly limited as long as it can remove the toner remaining on the image carrier, and can be appropriately selected according to the purpose. For example, the cleaning step can be performed by the cleaning unit. .

-Static elimination means and static elimination process-
The neutralization means is not particularly limited as long as it is a means for neutralizing by applying a neutralization bias to the image carrier, and can be appropriately selected according to the purpose. Examples thereof include a neutralization lamp.
The neutralization step is not particularly limited as long as it is a step of neutralizing by applying a neutralization bias to the image carrier, and can be appropriately selected according to the purpose. For example, the neutralization step is performed by the neutralization unit. it can.

-Recycling means and recycling process-
The recycling unit is not particularly limited as long as it is a unit that recycles the toner removed in the cleaning step to the developing device, and can be appropriately selected according to the purpose. Can be mentioned.
The recycling process is not particularly limited as long as it is a process for recycling the toner removed in the cleaning process to the developing device, and can be appropriately selected according to the purpose. For example, the recycling unit performs the recycling process. Can do.

-Control means and control process-
The control means is not particularly limited as long as it can control the movement of each means, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.
The control process is not particularly limited as long as it can control the movement of each process, and can be appropriately selected according to the purpose. For example, the control process can be performed by the control means.

Next, an example of an image forming apparatus according to the present invention will be described with reference to the drawings.
In addition, the number, position, shape, and the like of the following constituent members are not limited to the present embodiment, and can be set to a preferable number, position, shape, and the like in carrying out the present invention.

FIG. 1 is a schematic sectional view showing an example of the image forming apparatus of the present invention.
In FIG. 1, the image forming apparatus includes a copying apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.
The copying apparatus main body 150 is provided with an endless belt-like intermediate transfer member 50 at the center.
The intermediate transfer member 50 is stretched around the support rollers 14, 15, and 16 and can rotate clockwise in FIG. 1. An intermediate transfer member cleaning device 17 for removing residual toner on the intermediate transfer member 50 is disposed in the vicinity of the support roller 15. The intermediate transfer member 50 stretched between the support roller 14 and the support roller 15 is a tandem type in which four image forming units 18 of yellow, cyan, magenta, and black are arranged to face each other along the conveyance direction. A developing device 120 is disposed. In the vicinity of the tandem developing device 120, an exposure device 21 as the exposure member is disposed. A secondary transfer device 22 is disposed on the side of the intermediate transfer member 50 opposite to the side on which the tandem developing device 120 is disposed. In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt, is stretched around a pair of rollers 23, and the transfer paper conveyed on the secondary transfer belt 24 and the intermediate transfer member 50 are in contact with each other. Is possible. A fixing device 25 as the fixing unit is disposed in the vicinity of the secondary transfer device 22. The fixing device 25 includes a fixing belt 26 that is an endless belt, and a pressure roller 27 that is pressed against the fixing belt 26.
In the tandem image forming apparatus, a sheet reversing device 28 for reversing the transfer paper for image formation on both sides of the transfer paper is disposed in the vicinity of the secondary transfer device 22 and the fixing device 25. .

  Next, formation of a full-color image (color copy) using the tandem developing device 120 will be described. That is, first, a document is set on the document table 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and the document is set on the contact glass 32 of the scanner 300. 400 is closed.

  When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the contact glass 32. Immediately after that, the scanner 300 is driven, and the first traveling body 33 and the second traveling body 34 travel. At this time, light from the light source is irradiated by the first traveling body 33 and reflected light from the document surface is reflected by the mirror in the second traveling body 34 and is received by the reading sensor 36 through the imaging lens 35 to be color. An original (color image) is read and used as black, yellow, magenta, and cyan image information.

  Each image information of black, yellow, magenta, and cyan is stored in each image forming unit 18 (black image forming unit, yellow image forming unit, magenta image forming unit, and cyan image) in the tandem developing device 120. Each of the image forming units forms black, yellow, magenta, and cyan toner images. That is, each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means, and cyan image forming means) in the tandem type developing device 120 is a static image as shown in FIG. An electrostatic latent image carrier 10 (black electrostatic latent image carrier 10K, yellow electrostatic latent image carrier 10Y, magenta electrostatic latent image carrier 10M, and cyan electrostatic latent image carrier 10C); The charging device 160, which is the charging member for uniformly charging the electrostatic latent image carrier 10, and the electrostatic latent image carrier are exposed in an image corresponding to each color image based on each color image information (in FIG. 2). L), and an exposure device that forms an electrostatic latent image corresponding to each color image on the electrostatic latent image carrier 10, and the electrostatic latent image is converted into each color toner (black toner, yellow toner, magenta toner, And cyant A developing device 61 that is a developing unit that forms a toner image using each color toner by developing the toner image, a transfer charger 62 for transferring the toner image onto the intermediate transfer member 50, and a cleaning device 63. And a static eliminator 64, which can form single-color images (black image, yellow image, magenta image, and cyan image) based on the image information of each color. The black image, the yellow image, the magenta image, and the cyan image formed in this manner are respectively transferred to the black electrostatic latent image carrier 10K on the intermediate transfer member 50 that is rotationally moved by the support rollers 14, 15, and 16. Black image formed on top, yellow image formed on electrostatic latent image carrier 10Y for yellow, magenta image formed on electrostatic latent image carrier 10M for magenta, and electrostatic latent image carrier for cyan The cyan image formed on 10C is sequentially transferred (primary transfer). Then, the black image, the yellow image, the magenta image, and the cyan image are superimposed on the intermediate transfer member 50 to form a composite color image (color transfer image).

  On the other hand, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed out a sheet (recording paper) from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143. Each sheet is separated and sent to the paper feed path 146, transported by the transport roller 147, guided to the paper feed path 148 in the copying machine main body 150, and abutted against the registration roller 49 and stopped. Alternatively, the sheet feed roller 142 is rotated to feed out sheets (recording paper) on the manual feed tray 54, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped. . The registration roller 49 is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the sheet. Then, the registration roller 49 is rotated in synchronization with a synthesized color image (color transfer image) synthesized on the intermediate transfer member 50, and a sheet (recording paper) is interposed between the intermediate transfer member 50 and the secondary transfer device 22. And transferring the composite color image (color transfer image) onto the sheet (recording paper) by the secondary transfer device 22, thereby transferring the color image onto the sheet (recording paper). Is formed. The residual toner on the intermediate transfer member 50 after image transfer is cleaned by the intermediate transfer member cleaning device 17.

  The sheet (recording paper) on which the color image has been transferred is conveyed by the secondary transfer device 22 and sent to the fixing device 25, where the combined color image (color) is generated by heat and pressure. (Transfer image) is fixed on the sheet (recording paper). Thereafter, the sheet (recording paper) is switched by the switching claw 55 and discharged by the discharge roller 56 and stacked on the paper discharge tray 57, or switched by the switching claw 55 and reversed by the sheet reversing device 28 and transferred again. After being guided to the position and recording an image on the back surface, the image is discharged by the discharge roller 56 and stacked on the discharge tray 57.

  FIG. 3 is an explanatory diagram showing the dependency of the surface resistivity of the intermediate transfer belt as the image forming member of the present invention on the molding temperature, and the vertical axis indicates the surface resistivity (Ω / □, normal use) of the resin composition. A semi-logarithmic graph in which the horizontal axis is the heating temperature (° C.) is shown. Further, the shaded portion in FIG. 3 indicates the molding temperature range.

A characteristic A indicated by a solid line in FIG. 3 indicates a surface resistivity-heating temperature characteristic of the resin composition including the first thermoplastic resin and the conductive filler.
In the characteristic A, in the low temperature region lower than the molding temperature range, the surface resistivity is 1 × 10 ¹² Ω / □ to 1 × 10 ¹³ Ω / □, and the surface resistivity is higher than the heating temperature. There is little change. However, the surface resistivity decreases due to agglomeration of the conductive filler from the vicinity of the molding temperature range, and particularly when the surface resistivity often used in the intermediate transfer member is 1 × 10 ¹¹ Ω / □. The change in the surface resistivity with respect to the heating temperature increases rapidly.
For this reason, when the intermediate transfer member having a target value of the surface resistivity of 1 × 10 ¹¹ Ω / □ is manufactured, the variation in the surface resistivity becomes large.

The characteristic B indicated by the alternate long and short dash line in FIG. 3 is composed of the first thermoplastic resin, the second thermoplastic resin, and the conductive filler, and contains the conductive filler contained in the second thermoplastic resin. The surface resistivity-heating temperature characteristic of the resin composition whose rate is less than 40% is shown.
In the characteristic B, as compared with the characteristic A, by mixing the second thermoplastic resin having a low surface resistivity, the surface resistivity is lowered in the low temperature region, and the surface with respect to the heating temperature is reduced. Although the change in resistivity becomes gradual, the variation in surface resistivity becomes large.

A characteristic C indicated by a bold line in FIG. 3 includes the first thermoplastic resin, the second thermoplastic resin, and the conductive filler, and the conductive filler content of the second thermoplastic resin is 40. The surface resistivity-heating temperature characteristic of the resin composition which is% to 75% is shown.
In the characteristic C, compared with the characteristic B, the surface resistivity is further lowered in the low temperature region, stable at 1 × 10 ¹¹ Ω / □ in the molding temperature range, and the surface resistance with respect to the heating temperature. The rate change will be gradual.
The decrease in the surface resistivity in the low temperature region is considered to be due to the uneven distribution of the conductive filler in the island-shaped second thermoplastic resin.

The characteristic D shown by the broken line in FIG. 3 is composed of the first thermoplastic resin, the second thermoplastic resin, and the conductive filler, and the conductive filler content contained in the second thermoplastic resin. Shows a surface resistivity-heating temperature characteristic of a resin composition having a hardness higher than 75%.
In the characteristic D, compared with the characteristic C, the surface resistivity is higher in the low temperature region. This is because when the conductive filler is unevenly distributed only in the island-shaped second thermoplastic resin, the conductive filler of the first thermoplastic resin is reduced, and the conductivity between the island and the island is reduced. It is considered that the sex has declined. Therefore, in the said low temperature area | region and the said molding temperature range, it will remove | deviate from the said target value. Further, in the temperature region higher than the molding temperature range, the surface resistivity with respect to the heating temperature is drastically decreased, and thus the variation becomes larger. Therefore, the property C is preferable to the property D. .

Next, an example of the molding method will be described with reference to FIG.
FIG. 4 is an explanatory view showing an example of an extrusion molding apparatus.
In FIG. 4, in the extrusion molding, first, the temperature of the screw 212 is adjusted, and then the compound 214, which is the resin composition of the present invention, is put into the hopper 210, and the compound 214 is fed into the inside of the cylindrical die 216. To be. The heating temperature of the die 216 is set higher than the melting point of the compound 214, and the resin composition formed into a cylindrical shape is extruded from the mold. The extruded resin is cooled by a mandrel 218 and pulled by a take-up means 220 or inner and outer rollers (not shown).
In addition, a seamless belt can be produced by pouring the resin extruded and melted from the extruder 222 into a cylindrical extrusion mold (die 216). For the resin flowing from the extruder 222, a spiral die can be used in which the flow path is divided into eight in the mold and merged inside to flow spirally. In addition to this, a coat hanger die or the like in which the flow path is not divided and the resin wraps around the mold and joins at one place can be used. The resin then flows out of the lip. Further, it is formed by passing through an inner core that determines the circumference and shape, and is configured to be pulled while sandwiching the inside and outside with a roller or the like.
The surface resistivity can be adjusted by the take-up speed and the heating temperature.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
<Materials used>
First thermoplastic resin: polyvinylidene fluoride (Akema, Kynar 720) ... 86 parts by mass Second thermoplastic resin: polyetheresteramide (Sanyo Chemical Industries, Plectron AS, surface resistivity) 4.0 × 10 ⁶ Ω / □) ... 7 parts by mass Conductive filler: Furnace Black (Mitsubishi Chemical Corporation, # 3030B) ... 7 parts by mass

<Melt-kneading method>
85 parts by mass of the first thermoplastic resin, 8 parts by mass of the second thermoplastic resin, and 7 parts by mass of the conductive filler are all charged into a Henschel mixer (SPM, manufactured by Kawata). Then, stirring was performed to obtain a powder in which these materials were mixed. Next, the powder was melt-kneaded at a melting temperature of 180 ° C. or higher and 220 ° C. or lower as 1 pass with a biaxial kneader (Toshiba Machine Co., Ltd., TEM), and processed into pellets. Furthermore, 2pass melt kneading was performed using the biaxial kneader to obtain pellets 1-1.

<Seamless belt manufacturing method>
Next, the obtained pellet 1-1 was molded at a heating temperature of 200 ° C. with a cylindrical mold for melt kneading extrusion molding to obtain a seamless belt 1 having a circumference of 960 mm and an average thickness of 120 μm.

  Various physical properties of only the second thermoplastic resin were measured as follows.

<Measurement of melting point>
The melting point was measured as follows.
<< Measurement equipment >>
DSC: Q2000 manufactured by TA Instruments
<< Measurement conditions >>
Sample container: Aluminum sample pan (with lid)
Sample amount: 5mg
Reference: Aluminum sample pan (empty container)
Atmosphere: Nitrogen (flow rate 50 mL / min)
-First temperature rise process-
Starting temperature: -20 ° C
Temperature increase rate: 10 ° C / min
End temperature: 230 ° C
Holding time: 1 min
-Temperature lowering process-
Temperature drop rate: 10 ° C / min
End temperature: -50 ° C
Holding time: 5 min
-Second heating process-
Temperature increase rate: 10 ° C / min
End temperature: 230 ° C
* The maximum endothermic peak temperature in the first temperature raising process was defined as the melting point.

<Bleed rate in distilled water>
The bleed rate was determined by the following procedure, for example.
First, the second thermoplastic resin (mass A = 0.4 g) and distilled water (mass B = 34 g) were put in a glass container and hermetically sealed, and the glass container was dried with a dryer at 45 ° C. for 1 hour. . The dried glass container was vibrated for 40 minutes with an ultrasonic vibration generator, and the glass container was again dried with a dryer at 45 ° C. for 8 hours. The distilled water extract (mass D) in the glass container taken out from the dryer was put into a glass petri dish (mass C).
Next, the petri dish was dried with a dryer at 105 ° C. for 3 hours, and then taken out of the dryer and air-cooled for 1 hour. The petri dish (mass E) on which the solid content was precipitated was measured.
Then, the measured masses A to E were substituted into the following formula 1 to obtain the bleed rate.
[Formula 1]
(Bleed rate in distilled water (%)) = ((EC) / ((A / B) × D)) × 100

<Measurement of surface resistivity>
The surface resistivity was measured according to ASTM D257.

  Various physical properties of the conductive filler were measured as follows.

<Measurement of pH>
The pH was measured in a 25 ° C. environment using a pH meter (manufactured by Toa Chemical Co., Ltd., HM-30G).

<Measurement of average primary particle size>
The average primary particle diameter was determined by observing the carbon black particles with an electron microscope and calculating the arithmetic average diameter.

<Measurement of DBP oil absorption>
The DBP oil absorption was measured according to JIS K6217-4.

  Next, the seamless belt 1 was evaluated as follows.

<Confirmation that it has a sea-island structure>
Whether or not the seamless belt 1 has a sea-island structure was confirmed by observing a cross section of the seamless belt 1 with an electron microscope. Specifically, it observed using the scanning electron microscope.

<Measurement of conductive filler content>
Based on the obtained SEM image, the conductive filler content is determined based on the total area of the conductive filler contained in the second thermoplastic resin and the conductivity contained in the first thermoplastic resin. It calculated | required by calculating a ratio with the sum total of the area of a filler. Specifically, the obtained SEM image is read by image processing software, binarization is performed based on the image brightness, a thermoplastic resin and a conductive filler are distinguished, and a range for image processing is selected. Thus, the area of each conductive filler was determined.

<Measurement of surface resistivity>
The surface resistivity of the obtained seamless belt 1 was measured by a resistivity meter (manufactured by Mitsubishi Chemical Analytech Co., Ltd., Hiresta UX MCP-HT450, Hiresta URS probe) using a register table as an insulating plate. As the measurement conditions, 32 points were measured at intervals of 30 mm in the circumferential direction of the seamless belt 1 at an applied voltage of 500 V in an environment with a temperature of 23 ° C. and a relative humidity of 50%.

<Evaluation of range of variation in surface resistivity>
A common logarithm value was taken for each of the 32 measured values, and a difference obtained by subtracting the minimum value from the maximum value was calculated as the resistance variation.

<Bleed evaluation>
The obtained seamless belt 1 was cut into a strip having a size of 40 mm × 130 mm and wound around an image carrier removed from the image forming apparatus. The image carrier was stored for 14 days in an environment with a temperature of 50 ° C. and a relative humidity of 98%, and was taken out.
Remove the wound strip-shaped seamless belt from the taken image carrier, attach the image carrier to the image forming apparatus, output a magenta halftone image, and on the part where the seamless belt is wrapped, Whether or not an abnormal image such as white spots does not occur is visually evaluated based on the following criteria. In addition, if this evaluation is (double-circle) or (circle), it is a level which does not have a problem in actual use.
〔Evaluation criteria〕
◎: Not generated ○: No problem in actual use ×: Problem in actual use

  The evaluation results of the second thermoplastic resin, the conductive filler, and the seamless belt are shown in Table 1-1, Table 1-2, and Table 2, respectively.

(Example 2)
In Example 1, as shown in Table 1-1, the second thermoplastic resin was obtained from polyether ester amide (manufactured by Sanyo Chemical Industries, Plectron AS, surface resistivity 4.0 × 10 ⁶ Ω / □). Pellets obtained by melt-kneading in the same manner as in Example 1 except that the polyamide / polyether copolymer (Arkema, Pebax MH2030, surface resistivity 1.0 × 10 ⁷ Ω / □) was used instead. A seamless belt 2 was produced from 2-1 and subjected to various evaluations. The results are shown in Table 1-1, Table 1-2, and Table 2.

(Example 3)
In Example 1, as shown in Table 1-1, the second thermoplastic resin was obtained from polyether ester amide (manufactured by Sanyo Chemical Industries, Plectron AS, surface resistivity 4.0 × 10 ⁶ Ω / □). Pellets obtained by melt-kneading in the same manner as in Example 1 except that the polyamide / polyether copolymer (Arkema, Pebax MH1657, surface resistivity 1.5 × 10 ⁹ Ω / □) was used instead. The seamless belt 3 was produced from 3-1, and various evaluation was performed. The results are shown in Table 1-1, Table 1-2, and Table 2.

Example 4
In Example 1, as shown in Table 1-2, the conductive filler was changed, and the melt-kneading method was changed as follows. 4 was prepared and subjected to various evaluations. The results are shown in Table 1-1, Table 1-2, and Table 2.

<Melt-kneading method>
-Melt kneading 1
Here, melt kneading was performed only with the first thermoplastic resin and the conductive filler.
92.5 parts by mass of the first thermoplastic resin and 7.5 parts by mass of the conductive filler were added to a Henschel mixer (SPM, manufactured by Kawata Co., Ltd.) and stirred, and the mixed powder was mixed with a biaxial kneader. Melt kneading was performed by 1 pass (TEM, manufactured by Toshiba Machine Co., Ltd.), and pellet processing was performed to obtain pellet 4-1.

-Melt kneading 2-
Here, melt kneading was performed only with the second thermoplastic resin and the conductive filler.
The 99.5 parts by mass of the second thermoplastic resin and 0.5 parts by mass of the conductive filler were added to a Henschel mixer (SPM, manufactured by Kawata Co., Ltd.) and stirred, and the mixed powder was mixed with a biaxial kneader. Melt kneading was performed by 1 pass (TEM, manufactured by Toshiba Machine Co., Ltd.), and pellet processing was performed to obtain pellet 4-2.

-Melt kneading 3-
Melting and kneading 92 parts by mass of the pellet 4-1 obtained by the melt kneading 1 and 7 parts by mass of the pellet 4-2 obtained by the melt kneading 2 using a twin-screw kneader (manufactured by Toshiba Machine Co., Ltd., TEM). 1 pass was performed and pellet processing was performed to obtain pellet 4-3.

(Example 5)
In Example 1, except that the conductive filler was changed as shown in Table 1-2, melt kneading was performed in the same manner as in Example 1, and the seamless belt 5 was produced from the obtained pellets 5-1, and various types were obtained. Evaluation was performed. The results are shown in Table 1-1, Table 1-2, and Table 2.

(Example 6)
In Example 1, except that the conductive filler was changed as shown in Table 1-2, melt kneading was performed in the same manner as in Example 1, and the seamless belt 6 was produced from the obtained pellets 6-1, and various types were obtained. Evaluation was performed. The results are shown in Table 1-1, Table 1-2, and Table 2.

(Example 7)
In Example 4, except that the conductive filler was changed as shown in Table 1-2, melt kneading was performed in the same manner as in Example 4, and a seamless belt 7 was produced from the obtained pellets 7-3. Evaluation was performed. The results are shown in Table 1-1, Table 1-2, and Table 2.

(Example 8)
In Example 6, as shown in Table 1-1, the second thermoplastic resin was changed from polyether ester amide (manufactured by Sanyo Chemical Industries, Peletron AS, surface resistivity 4.0 × 10 ⁶ Ω / □). Obtained by melt-kneading in the same manner as in Example 6 except that it was replaced with a polyolefin / polyether copolymer (BASF, Irgastat P18 FCA, surface resistivity 8.0 × 10 ⁷ Ω / □). A seamless belt 8 was prepared from the pellets 8-1 and various evaluations were performed. The results are shown in Table 1-1, Table 1-2, and Table 2.

Example 9
In Example 6, as shown in Table 1-1, the second thermoplastic resin was changed from a polyether ester amide (manufactured by Sanyo Chemical Industries, Peletron AS) to a polyamide / polyether copolymer (manufactured by Ion Phase, U3). The seamless belt 9 was produced from the obtained pellets 9-1 and subjected to various evaluations, except that the composition was replaced with a). The results are shown in Table 1-1, Table 1-2, and Table 2.

(Example 10)
In Example 1, as shown in Table 1-1, the second thermoplastic resin was obtained from polyether ester amide (manufactured by Sanyo Chemical Industries, Plectron AS, surface resistivity 4.0 × 10 ⁶ Ω / □). Instead of the polyamide / polyether copolymer (Arkema, Pebax MH1657, surface resistivity 1.5 × 10 ⁹ Ω / □), except that the conductive filler was changed as shown in Table 1-2, Melt-kneading was performed in the same manner as in Example 1, and a seamless belt 10 was produced from the obtained pellets 10-1 and subjected to various evaluations. The results are shown in Table 1-1, Table 1-2, and Table 2.

(Comparative Example 1)
In Example 4, except that the melt-kneading method was changed as described below, the seamless belt 11 was produced from the obtained pellets 11-3 in the same manner as in Example 4, and various evaluations were performed. The results are shown in Table 1-1, Table 1-2, and Table 2.

<Melt-kneading method>
85 parts by mass of the first thermoplastic resin, 7 parts by mass of the second thermoplastic resin, and 6 parts by mass of the conductive filler are charged into a Henschel mixer (SPM, manufactured by Kawata Corporation). Stirring was performed, and the mixed powder was melt-kneaded for 2 passes by a biaxial kneader (manufactured by Toshiba Machine Co., Ltd., TEM), and pelletized to obtain pellets 11-1.

(Comparative Example 2)
In Example 7, the seamless belt 12 was produced from the obtained pellets 12-3 and subjected to various evaluations in the same manner as in Example 7 except that the melt kneading method was changed as follows. The results are shown in Table 1-1, Table 1-2, and Table 2.
<Melt-kneading method>
-Melt kneading 4-
Here, melt kneading was performed only with the first thermoplastic resin and the conductive filler.
92.5 parts by mass of the first thermoplastic resin and 7.5 parts by mass of the conductive filler were added to a Henschel mixer (SPM, manufactured by Kawata Co., Ltd.) and stirred, and the mixed powder was mixed with a biaxial kneader. Melt kneading was performed by 1 pass (TEM, manufactured by Toshiba Machine Co., Ltd.), and pellet processing was performed to obtain pellets 12-1.

-Melt kneading 5-
Here, melt kneading was performed only with the second thermoplastic resin and the conductive filler.
99.9 parts by mass of the second thermoplastic resin and 0.1 part by mass of conductive filler were added to a Henschel mixer (SPM, manufactured by Kawata Co., Ltd.) and stirred, and the mixed powder was mixed with a biaxial kneader. Melt kneading was performed by 1 pass (TEM, manufactured by Toshiba Machine Co., Ltd.), and pellet processing was performed to obtain pellet 12-2.

-Melt kneading 6
92 parts by mass of pellets 12-1 obtained by melt kneading 4 and 8 parts by mass of pellets 12-2 obtained by melt kneading 5 were melt kneaded by a biaxial kneader (manufactured by Toshiba Machine Co., Ltd., TEM). 1 pass was performed and pellet processing was performed to obtain pellet 12-3.

(Comparative Example 3)
In Example 1, as shown in Table 1-1, the second thermoplastic resin was obtained from polyether ester amide (manufactured by Sanyo Chemical Industries, Plectron AS, surface resistivity 4.0 × 10 ⁶ Ω / □). Pellets obtained by melt-kneading in the same manner as in Example 1 except that the polyamide / polyether copolymer (Arkema Co., Pebax MV1074, surface resistivity 2.5 × 10 ⁹ Ω / □) was used. A seamless belt 13 was produced from 13-1 and subjected to various evaluations. The results are shown in Table 1-1, Table 1-2, and Table 2.

From Table 2, in Examples 1 to 10, 40% to 75% of the conductive filler is present in the second thermoplastic resin, and the melting point of the second thermoplastic resin is 170 ° C. or higher. Since it is 220 ° C., the variation range of the surface resistivity in the seamless belt is within one, whereas in Comparative Examples 1 to 3, the variation range of the surface resistivity is larger than one.
From Table 1-1, when Example 1 is compared with Example 3, the variation in the surface resistivity is smaller in Example 3 where the melting point is 200 ° C. or more than in Example 1.
Further, from Table 1-2, when Example 1 and Example 4 are compared, Example 4 having a smaller average primary particle size exhibits less variation in surface resistivity than Example 1. Further, when Example 4 and Example 5 are compared, the variation in surface resistivity is smaller in Example 5 having a pH of 9 or more than in Example 4. Furthermore, from a comparison between Example 5 and Example 6, DBP oil absorption amount variation of the surface resistivity than the Example 5 towards the 200 cm ^3/100 g Example 6 below is reduced.
Regarding the bleed property evaluation, comparing Example 1 to Example 3, Example 2 and Example 3 using the polyamide / polyether copolymer as the second thermoplastic resin were more effective than Example 1. It can be confirmed that the image quality after leaving at high temperature and high humidity is good.

As an aspect of this invention, it is as follows, for example.
<1> A sea-island structure including a first thermoplastic resin, a second thermoplastic resin, and a conductive filler, wherein the second thermoplastic resin is in an island shape in a continuous phase of the first thermoplastic resin. A resin composition comprising:
In the cross section of the resin composition, the total area of the conductive filler existing in both the first thermoplastic resin and the second thermoplastic resin is present in the second thermoplastic resin. The area ratio of the conductive filler is 40% to 75%,
The second thermoplastic resin is a resin composition having a melting point of 170 ° C. or higher and 220 ° C. or lower.
<2> The resin composition according to <1>, wherein the content ratio of the second thermoplastic resin is 2% by mass or more and 7% by mass or less of the entire resin composition.
<3> The resin composition according to any one of <1> to <2>, wherein a bleed rate of the second thermoplastic resin into distilled water is 4% by mass or less.
<4> The resin composition according to any one of <1> to <3>, wherein the second thermoplastic resin is a block copolymer having a polyethylene oxide unit.
<5> The resin composition according to <4>, wherein the block copolymer having a polyethylene oxide unit is a polyamide / polyether copolymer.
<6> The resin composition according to any one of <1> to <5>, wherein the melting point of the second thermoplastic resin is 200 ° C. or higher.
<7> DBP oil absorption amount of the conductive filler ^is a resin composition according to any one of <6> to 200 cm 3/100 g or less is the <1>.
<8> The average primary particle size of the conductive filler is 10 nm or more and 40 nm or less,
The resin composition according to any one of <1> to <7>, wherein the conductive filler has a pH of 9 or more.
<9> An image forming member comprising the resin composition according to any one of <1> to <8>.
<10> An image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the image carrier, a developing unit that develops the electrostatic latent image into a toner image, and the toner image as a recording medium An image forming apparatus having transfer means for transferring,
The image forming apparatus, wherein the transfer unit is the image forming member according to <9>.

210 hopper 212 screw 214 compound 216 die 218 mandrel 220 take-up device 222 extruder

JP 04-255332 A

Claims (10)

A resin having a sea-island structure including a first thermoplastic resin, a second thermoplastic resin, and a conductive filler, wherein the second thermoplastic resin is in an island shape in a continuous phase of the first thermoplastic resin. A composition comprising:
In the cross section of the resin composition, the total area of the conductive filler existing in both the first thermoplastic resin and the second thermoplastic resin is present in the second thermoplastic resin. The area ratio of the conductive filler is 40% to 75%,
The resin composition, wherein the second thermoplastic resin has a melting point of 170 ° C. or higher and 220 ° C. or lower.   2. The resin composition according to claim 1, wherein the content of the second thermoplastic resin is 2% by mass or more and 7% by mass or less of the entire resin composition.   The resin composition according to any one of claims 1 to 2, wherein a bleed rate of the second thermoplastic resin into distilled water is 4% by mass or less.   The resin composition according to any one of claims 1 to 3, wherein the second thermoplastic resin is a block copolymer having a polyethylene oxide unit.   The resin composition according to claim 4, wherein the block copolymer having a polyethylene oxide unit is a polyamide / polyether copolymer.   The resin composition according to any one of claims 1 to 5, wherein the melting point of the second thermoplastic resin is 200 ° C or higher. DBP oil absorption amount of the conductive ^filler, the resin composition according to any one of claims 1 to 6 is 200 cm 3/100 g or less. The average primary particle size of the conductive filler is 10 nm or more and 40 nm or less,
The resin composition according to any one of claims 1 to 7, wherein the conductive filler has a pH of 9 or more.   An image forming member comprising the resin composition according to claim 1. An image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the image carrier, a developing unit that develops the electrostatic latent image into a toner image, and a transfer that transfers the toner image to a recording medium. An image forming apparatus comprising:
The image forming apparatus according to claim 9, wherein the transfer unit is the image forming member according to claim 9.