JP2013245288A - Conductive resin composition, transfer belt for electrophotography and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive resin composition having good dispersibility of a conductive material and excellent conductivity, a molded body obtained by molding the conductive resin composition, a transfer belt for electronic photography obtained by extruding the conductive resin composition into a circular shape and having excellent conductivity and an image forming device provided with the transfer belt.SOLUTION: A conductive resin composition is obtained by melt-mixing a polyarylene sulfide resin, an amorphous polymer and a conductive material, wherein the ratio V6p/V6a of a melt viscosity (V6p) of the polyarylene sulfide resin to the melt viscosity (V6a) of the amorphous polymer measured at 300°C is in the range of ≥0.005. A molded body and a transfer belt for an electrophotography each using the conductive resin composition, and an image forming device provided with the transfer belt are provided.

Description

  The present invention relates to a conductive resin composition, an electrophotographic transfer belt, and an image forming apparatus.

  A polyarylene sulfide resin (hereinafter sometimes abbreviated as “PAS resin”) represented by a polyphenylene sulfide resin (hereinafter sometimes abbreviated as “PPS resin”) has excellent heat resistance, flame retardancy, rigidity, It has suitable properties as an engineering plastic such as chemical resistance and electrical insulation, and is used for various electrical / electronic parts, mechanical parts, automobile parts, etc. mainly for injection molding.

  When this polyarylene sulfide resin is applied to conductive applications such as an electrophotographic transfer belt or an antistatic tray, it is necessary to add a conductive material such as carbon to make the resin conductive in a uniform semiconductor region. Polyarylene sulfide resins are not necessarily excellent in carbon dispersibility, and have a problem that the dispersion state of carbon changes during extrusion molding, resulting in non-uniform conductivity. If the conductivity of the transfer belt is not uniform, characters may be lost or toner may be scattered during printing. Since polyarylene sulfide resins have insufficient toughness, they have often been used with improved strength by using a reinforcing agent such as glass fiber. In applications where smoothness is required, non-reinforced materials that do not use glass fiber or the like are required.

  Therefore, by blending a polyamide resin with a polyarylene sulfide resin, the toughness of the resin is increased, and the dispersion state of carbon in the resin composition is made uniform to provide relatively uniform conductivity. It has been reported that a transfer belt can be obtained (see Patent Documents 1 and 2). However, it cannot be said that the dispersion performance of the conductive material by the polyamide resin is sufficient.

JP 2009-20154 A JP 2010-143970 A

  Accordingly, the problem to be solved by the present invention is that a conductive resin composition having good dispersibility of the conductive material and excellent conductivity, and molding having excellent conductivity obtained by molding the conductive resin composition. It is an object of the present invention to provide an electrophotographic transfer belt having excellent conductivity obtained by extruding the conductive resin composition in a ring shape and an image forming apparatus provided with the transfer belt.

  As a result of intensive studies to solve the above problems, the present inventors have made a polyarylene sulfide resin, an amorphous polymer, and a conductive material by melting and kneading them under specific conditions. By using an arylene sulfide resin as a matrix, a sea-island structure in which the amorphous polymer is dispersed in the form of particles can be formed, the concentration of the conductive material of one phase is increased, and an efficient conductive network is formed. As a result, the present inventors have found that the electrical conductivity of the present invention is drastically improved.

That is, the present invention is a conductive resin composition comprising polyarylene sulfide resin (A), amorphous polymer (B) and conductive material (C) as essential components,
The ratio V6p / V6a between the melt viscosity (V6p) of the polyarylene sulfide resin (A) measured at 300 ° C. and the melt viscosity (V6a) of the amorphous polymer (B) measured at 300 ° C. is 0.005 to 0. It is related with the conductive resin composition characterized by being in the range of .2.

  The present invention also provides a molded body obtained by molding the above-described resin composition, particularly a sheet or film, and further an electrophotographic transfer belt obtained by extrusion-molding the above-described conductive resin composition, The present invention also relates to an image forming apparatus provided with the electrophotographic transfer belt described above.

  According to the present invention, a conductive resin composition excellent in dispersibility of a conductive material and exhibiting excellent conductivity, a molded article excellent in conductivity obtained by molding the conductive resin composition, and the conductivity An electrophotographic transfer belt excellent in conductivity obtained by extrusion molding a resin composition in a ring shape and an image forming apparatus provided with the transfer belt can be provided.

FIG. 1 is a photomicrograph of the conductive film (1) obtained in Example 1. FIG. 2 is a photomicrograph of the conductive film (2) obtained in Example 2. FIG. 3 is a photomicrograph of the conductive film (3) obtained in Comparative Example 1. FIG. 4 is a photomicrograph of the conductive film (4) obtained in Comparative Example 2. FIG. 5 is a photomicrograph of the conductive film (5) obtained in Comparative Example 3.

  The present invention relates to a conductive resin composition comprising a polyarylene sulfide resin (A), an amorphous polymer (B), and a conductive material (C) as essential components, the polyarylene sulfide measured at 300 ° C. The ratio V6p / V6a between the melt viscosity (V6p) of the resin (A) and the melt viscosity (V6a) of the amorphous polymer (B) measured at 300 ° C. is in the range of 0.01 to 0.2.

<Polyarylene sulfide resin>
The polyarylene sulfide resin (A) used in the present invention has a resin structure having a structure in which an aromatic ring and a sulfur atom are bonded as a repeating unit. Specifically, the polyarylene sulfide resin (A) is represented by the following formula (1):

(Wherein, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a nitro group, an amino group, a phenyl group, a methoxy group, or an ethoxy group). It is a resin having a structural site as a repeating unit.

Here, in the structural part represented by the formula (1), it is particularly preferable that R ¹ and R ² in the formula are hydrogen atoms from the viewpoint of the mechanical strength of the polyarylene sulfide resin (A). In this case, those bonded at the para position represented by the following formula (2) and those bonded at the meta position represented by the following formula (3) are exemplified.

Among these, the heat resistance of the polyarylene sulfide resin (A) is that the bond of the sulfur atom to the aromatic ring in the repeating unit is a structure bonded at the para position represented by the structural formula (2). It is preferable in terms of crystallinity.

  In addition, the polyarylene sulfide resin (A) includes not only the structural portion represented by the formula (1) but also the following structural formulas (4) to (7).

The structural site represented by the formula (1) may be included at 30 mol% or less of the total with the structural site represented by the formula (1). In particular, in the present invention, the structural sites represented by the above formulas (4) to (7) are preferably 10 mol% or less from the viewpoint of the heat resistance and mechanical strength of the polyarylene sulfide resin (A). In the case where the polyarylene sulfide resin (A) contains a structural moiety represented by the above formulas (4) to (7), the bonding mode thereof may be either a random copolymer or a block copolymer. May be.

  The polyarylene sulfide resin (A) has the following formula (8) in its molecular structure.

May have a trifunctional structural site represented by the formula (1) or a naphthyl sulfide bond, but is preferably 3 mol% or less, particularly 1 mol%, based on the total number of moles with other structural sites. The following is preferable.

  As the polyarylene sulfide resin (A) used in the present invention, a polyarylene sulfide resin (A) having a melt viscosity (V6p) measured at 300 ° C. in the range of 5 to 1,000 [Pa · s] can be used. Since it is possible to further suppress discharge unevenness during molding and to easily obtain a molded product having a uniform thickness, 100 [Pa · s] or more is a preferable range. On the other hand, since the gelation tendency at the time of melt-kneading is suppressed and a molded product excellent in surface smoothness tends to be obtained, the range is 500 [Pa · s] or less, and further 300 [Pa · s]. A range is preferred.

  However, in the present invention, “melt viscosity measured at 300 ° C.” means that the former / the latter ratio of temperature 300 ° C., load 1.96 MPa, orifice length and orifice diameter using a Koka flow tester. Represents the melt viscosity after holding for 6 minutes using an orifice that is 10/1.

  The number of terminal carboxy groups of the polyarylene sulfide resin (A) used in the present invention is not particularly limited as long as it does not impair the effects of the present invention, but the terminal carboxy group is 25-60 (μmol / mol in the resin). It is preferable to use what is contained in the ratio of g). When the terminal carboxy group is 25 (μmol / g) or more, the reactivity with various additives becomes more sufficient, and the intended effects such as mechanical strength such as thermal shock resistance are more easily exhibited. , 60 (μmol / g) or less, the gelation tendency at the time of melt-kneading can be suppressed, and a molded product excellent in surface smoothness can be easily obtained.

Further, the shape of the polyarylene sulfide resin (A) is not particularly limited as long as it does not impair the effects of the present invention, but the non-Newton index is in the range of 0.90 to 1.25, so-called It is preferable to use one having a linear structure. If the non-Newtonian index is 1.25 or less, the degree of branching can be suppressed, and the proportion of the terminal carboxy group can be easily adjusted to an appropriate range. However, the non-Newtonian index (N value) is measured by measuring the shear rate and shear stress using a capillograph at 300 ° C, the ratio of the orifice length (L) to the orifice diameter (D), and L / D = 40. SR = K · SS ^N where SR is the shear rate (second −1), SS is the shear stress (dyne / cm ² ), and K is a constant. ] Is an N value calculated using

As described above, the polyarylene sulfide resin used in the present invention preferably has a linear structure with a low degree of branching having a non-Newtonian index of 0.90 to 1.25 among linear structures. The resin not only has excellent flexibility, but also can improve mechanical strength, in particular, thermal shock resistance.
Furthermore, since the compatibility with the amorphous polymer (B) is improved and the moldability and the thermal shock resistance are further improved, the alkali metal salt in the resin (A) is 20 [μmol / g] or less in the resin. It is preferable to use the thing of this ratio.

  The polyarylene sulfide resin (A) used in the present invention can be produced, for example, by the following method described in International Publication No. 2010/58713 pamphlet. That is, in the presence of a non-hydrolyzable organic solvent, a hydrous alkali metal sulfide, or a hydrous alkali metal hydrosulfide and an alkali metal hydroxide, and an aliphatic cyclic compound that can be ring-opened by hydrolysis, Solid alkali metal sulfide and the aliphatic cyclic compound are reacted at a temperature not lower than the boiling point of the alkali metal sulfide and dehydrated at a temperature at which water is removed by azeotropy, specifically in the range of 80 to 220 ° C. A slurry (I) containing an alkali metal salt of a hydrolyzate of the above is produced, an aprotic polar organic solvent is further added to the obtained slurry (I), and the water content in the reaction system is reduced to an aprotic polar organic solvent. Dehydration is performed by distilling to 0.02 mol or less per mol.

  Next, in the slurry (I) obtained through the dehydration step, a polyhaloaromatic compound, an alkali metal hydrosulfide, and an alkali metal salt of a hydrolyzate of the aliphatic cyclic compound are aprotic. Polymerization is carried out by reacting with 1 mol of the polar organic solvent at a temperature of 180 to 300 ° C. with a water content existing in the reaction system of 0.02 mol or less.

  The proportion of the alkali metal salt of the hydrolyzate of the aliphatic cyclic compound in the reaction system is 0.01 mol or more and less than 0.9 mol with respect to 1 mol of sulfur atoms present in the reaction system. However, the range of 0.04 to 0.4 mol is particularly preferable because the effect of suppressing side reactions becomes remarkable.

  Further, the amount of the polyhaloaromatic compound at the time of carrying out the polymerization reaction is preferably in the range of 0.8 to 1.2 mol, particularly 0.9 to 1 per mol of sulfur atom in the reaction system. A range of 1 mol is preferable from the viewpoint of obtaining a crude polyarylene sulfide resin having a higher molecular weight.

  In the polymerization reaction, an aprotic polar organic solvent may be further added. The total amount of the aprotic polar organic solvent present in the reaction is not particularly limited, but it is aprotic so as to be 0.6 to 10 moles per mole of sulfur atoms present in the reaction system. A polar organic solvent can be added.

Next, the reaction mixture containing the crude polyarylene sulfide resin obtained by the polymerization reaction is purified. The method is not particularly limited. For example, (1) after completion of the polymerization reaction, the reaction mixture is first left as it is, or after adding an acid or a base, the solvent is distilled off under reduced pressure or normal pressure. Then, the solid after evaporation of the solvent is washed once or twice with a solvent such as water, acetone, methyl ethyl ketone, alcohol, etc., and further neutralized, washed with water, filtered and dried, or (2) completion of the polymerization reaction Thereafter, the reaction mixture is mixed with a solvent such as water, acetone, methyl ethyl ketone, alcohol, ether, halogenated hydrocarbon, aromatic hydrocarbon or aliphatic hydrocarbon (soluble in the polymerization solvent used and at least a polyarylene sulfide resin ( A solvent which is a poor solvent for A) is added as a precipitating agent, and solid products such as polyarylene sulfide resin (A) and inorganic salts are precipitated. Or (3) after completion of the polymerization reaction, after adding a reaction solvent (or an organic solvent having an equivalent solubility in a low molecular weight polymer) to the reaction mixture and stirring. Examples of the method include filtering, removing the low molecular weight polymer, and then washing once or twice with a solvent such as water, acetone, methyl ethyl ketone, and alcohol, followed by neutralization, washing with water, filtration, and drying.
In the present invention, a commercially available polyarylene sulfide resin can be used. As such a commercially available polyarylene sulfide resin (both are trade names), for example, MA-505, MA-510 manufactured by DIC Corporation, MA-520 etc. are mentioned.

<Amorphous polymer (B)>
The conductive resin composition of the present invention can form a microphase-separated structure in which the amorphous polymer (B) is dispersed in the form of particles using the polyarylene sulfide resin (A) as a matrix, so-called sea-island structure, This increases the concentration of the conductive material in this phase and forms an efficient conductive network, so that the conductivity is dramatically improved.

  The conductive resin composition has a microphase separation structure in which the amorphous polymer (B) is dispersed in the form of particles using the polyarylene sulfide resin (A) as a matrix. The conductive material (C) is dispersed in the amorphous polymer (B) dispersed in the material.

In order to adopt such a microphase separation structure, the melt viscosity (V6a) measured at 300 ° C. of the amorphous polymer (B) is in the range of 20 to 5000 [Pa · s], preferably 500 to 4500 [Pa -The range of S]. Further, in order to form the microphase separation structure, it is desirable that the difference in melt viscosity with the polyarylene sulfide resin (A) is small during melt kneading. For this reason, the ratio V6p / V6a of the melt viscosity (V6p) of the polyarylene sulfide resin (A) measured at 300 ° C. and the melt viscosity (V6a) of the amorphous polymer (B) measured at 300 ° C. is 0.00. The range is 005 or more, preferably 0.01 or more.
When the V6p / V6a value is smaller than 0.005, the dispersibility of the conductive particles during melt kneading tends to be poor, and coarse particles tend to be generated. Therefore, if the V6p / V6a value is in the range of 0.005 or more, the coarse particles of the conductive particles (C) are not generated, and the particle size of the conductive particles (C) is preferably 20 [μm] or less, preferably Is in the range of 0.005 to 5 [μm]. The particle size value 0.005 [μm] of the conductive particles (C) is a limit value for observation using a microscope. On the other hand, the upper limit of the V6p / V6a value tends to gel because the polyarylene sulfide resin tends to be a relatively high molecular weight product. For this reason, the V6p / V6a value is preferably in the range of 0.2 or less, and further 0 The range of 1 or less is more preferable.

  The composition ratio of the amorphous polymer (B) in the resin composition of the present invention is in the range of 10 to 100 parts by mass, preferably 10 to 50 parts by mass with respect to 100 parts by mass of the polyarylene sulfide resin.

Examples of the amorphous polymer used in the present invention include polyphenylene ether resin (PPE), polyether sulfone resin (PES), polyarylate resin (PAR), and polyamideimide resin (PAI). Polyether sulfone resin is preferred because of its superior properties.
As the polyether sulfone resin preferably used in the present invention, the following formula (9)

Is a polyether sulfone resin containing 80 mol% or more of the repeating unit represented by the formula (hereinafter referred to as “unit of formula (9)”). There is an advantage that it is more excellent in heat resistance. From this viewpoint, it is more preferable that the unit of the formula (9) is 90 mol% or more, and a polyether sulfone resin substantially consisting of the unit of the formula (9) is particularly preferable. In the polyether sulfone resin, for example, a chlorine atom, a hydroxyl group, a metal alkoxide group, an alkoxy group or the like may be bonded to a terminal group due to production conditions.

  Commercially available polyether sulfone resins can be used in the present invention. Examples of such commercially available polyether sulfone resins (both trade names) include Sumika Excel PES3600P, 4100P, 4800P manufactured by Sumitomo Chemical Co., Ltd. 5200P, etc., Solvay Specialty Polymers, Inc. Veradel A-201, A-301, etc., BASF Ultrazone E1010, E2010, E3010, etc. are mentioned.

  The polyphenylene ether resin preferably used in the present invention includes a homopolymer and / or copolymer polyphenylene ether resin having a repeating unit represented by the following formula (10).

(Where R ₁ , R ₂ , R ₃ and R ₄ are each hydrogen, halogen, primary or secondary lower alkyl group having 1 to 7 carbon atoms, phenyl group, haloalkyl group, aminoalkyl group, It is selected from the group consisting of a hydrocarbonoxy group or a halohydrocarbonoxy group in which at least two carbon atoms separate a halogen atom and an oxygen atom, and may be the same or different. )

  Of these, specific examples include poly (2,6-dimethyl-1,4-phenylene ether), poly (2-methyl-6-ethyl-1,4-phenylene ether), poly (2-methyl- 6-phenyl-1,4-phenylene ether), poly (2,6-dichloro-1,4-phenylene ether) and the like, and 2,6-dimethylphenol and other phenols (for example, 2,3 , 6-trimethylphenol and 2-methyl-6-butylphenol) and other polyphenylene ether copolymers. Of these, poly (2,6-dimethyl-1,4-phenylene ether) and a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol are preferable, and poly (2,6-dimethyl-1 , 4-phenylene ether).

<Conductive material (C)>
The conductive material (C) used in the present invention is not particularly limited as long as it can impart conductivity by being blended. For example, known conductive material materials conventionally used in the field of electronic parts such as electrophotographic transfer belts and antistatic trays can be used. Specific examples of the conductive material (C) include, for example, natural graphite, artificial graphite, coke, low graphitizable carbon such as low-temperature calcined carbon, non-graphitizable carbon obtained by carbonizing an organic substance, metal composite oxide, For example, compounds such as perovskite group, crystalline or amorphous oxides such as zinc, tin, indium and antimony, or metal oxide fine particles such as oxides composed of combinations of these elements, polyacetylene, polyaniline, polythiophene, Examples thereof include conductive or semiconductive polymers such as polymers having sulfonic acid or carboxylic acid in the side chain, and among these, carbon is preferable. The average primary particle size of the conductive material, particularly carbon, is usually 0.5 to 50 [nm], preferably 15 to 40 [nm].

  The composition ratio of the conductive material (C) in the conductive resin composition of the present invention is in the range of 1 to 30 parts by mass, preferably 5 to 25 parts by mass with respect to 100 parts by mass of the polyarylene sulfide resin. In particular, from the viewpoint of imparting an excellent surface resistance of about 10 9 to 11 Ω / □ to the resin composition, 5 to 20 parts by mass is preferable with respect to 100 parts by mass of the polyarylene sulfide resin. Two or more kinds of conductive materials can be used in combination, and in that case, the total amount thereof may be within the above range.

<Other ingredients>
In the conductive resin composition of the present invention, usual additions such as an antioxidant, a heat stabilizer, a lubricant, a crystal nucleating agent, an ultraviolet light inhibitor, a colorant, a flame retardant, etc., within a range not impairing the effects of the present invention. Agents and small amounts of other polymers can be blended. Further, for the purpose of controlling the degree of crosslinking of the polyarylene sulfide resin (A), a crosslinking agent such as a normal peroxide and a thiophosphinic acid metal salt described in JP-A-59-131650, or JP-A Crosslinking inhibitors such as dialkyltin dicarboxylates and aminotriazoles described in JP-A-58-204045 and JP-A-58-204046 can also be blended.

  In the conductive resin composition of the present invention, the fibrous and / or granular reinforcing agent is not an essential component, but can be blended as necessary. The reinforcing agent can be blended in a range not exceeding 400 parts by mass with respect to 100 parts by mass of the resin component in the transfer belt. Usually, it is possible to further improve the strength, rigidity, heat resistance, dimensional stability and the like by blending the reinforcing agent in the range of 1 to 300 parts by mass.

  Examples of the fibrous reinforcing agent include glass fibers, shirasu glass fibers, alumina fibers, silicon carbide fibers, ceramic fibers, asbestos fibers, stone fiber fibers, and metal fibers, carbon fibers, and the like.

  Examples of granular reinforcing agents include silicates such as wollastonite, sericite, kaolin, mica, clay, bentonite, asbestos, talc, and alumina silicate, and metal oxides such as alumina, silicon chloride, magnesium oxide, zirconium oxide, and titanium oxide. And carbonates such as calcium carbonate, magnesium carbonate, and dolomite, sulfates such as calcium sulfate and barium sulfate, glass beads, boron nitride, silicon carbide, and silica. These may be hollow.

  Two or more reinforcing agents can be used in combination, and can be used after pretreatment with a coupling agent such as silane or titanium if necessary.

<Manufacture of resin composition>
The conductive resin composition of the present invention can be produced, for example, by the method shown below.
First, a polyarylene sulfide resin (A), an amorphous polymer (B), a conductive material (C), and a mixture containing other additives and reinforcing agents as required are melt-kneaded, and the extruded kneaded product is cooled. .

  The temperature at which the melt kneading is performed is a temperature equal to or higher than the melting points of the polyarylene sulfide resin and the amorphous polymer. For example, when the amorphous polymer is a polyether sulfone resin, the temperature is usually in the range of 270 to 380 ° C.

  Specifically, the polyarylene sulfide resin (A), the amorphous polymer (B), and the conductive material (C) are further mixed uniformly with a tumbler or a Henschel mixer, if necessary, Then, it is put into a twin screw extruder, and the ratio (discharge amount / screw rotation number) between the discharge amount (kg / hr) of the resin component and the screw rotation number (rpm) is 0.02 to 0.2 (kg / hr). / Rpm) and a melt kneading method. By producing under such conditions, the polyarylene sulfide resin (A) is used as a matrix to form a sea-island structure in which the amorphous polymer (B) is finely dispersed in particles having an average particle diameter of 1 to 100 [μm]. In addition, the conductive material (C) can actively penetrate into one phase and be uniformly dispersed. At that time, the particle diameter of the conductive material (C) dispersed in the amorphous polymer (B) is in the range of 0.005 to 5 [μm], preferably 0.005 to 1 [μm], as measured by SEM. It is. Thus, by forming the sea-island structure, the concentration of the conductive material of one phase is increased, an efficient conductive network is formed, and high conductivity is expressed.

  The above production method will be described in more detail. A method may be mentioned in which the above-described components are put into a twin-screw extruder and melt kneaded under temperature conditions of a set temperature of 310 ° C. and a resin temperature of about 330 ° C. At this time, the discharge amount of the resin component is in the range of 4 to 40 kg / hr at a rotation speed of 200 rpm. Especially, it is preferable that it is 10-25 kg / hr from the point of a dispersibility. Therefore, the ratio (discharge amount / screw rotation number) between the resin component discharge amount (kg / hr) and the screw rotation speed (rpm) is particularly 0.05 to 0.125 (kg / hr / rpm). Is preferred. Further, the torque of the twin screw extruder is within a range where the maximum torque is 20 to 100 (A), particularly 25 to 80 (A), and the polyarylene sulfide resin (A) of the conductive material (C) is matrixed. As mentioned above, it is preferable from the point that the sea-island structure in which the amorphous polymer (B) is finely dispersed is formed and the dispersibility of the conductive material (C) is good.

  Moreover, when adding a reinforcing agent and an additive among the said mixing | blending components, it is preferable from a dispersible viewpoint to throw in into this extruder from the side feeder of the said twin-screw extruder. The position of the side feeder is preferably such that the ratio of the distance from the extruder resin charging part to the side feeder with respect to the total screw length of the biaxial extruder is 0.1 to 0.6. Among these, 0.2 to 0.4 is particularly preferable.

  The resin composition melt-kneaded in this way is obtained as pellets and then left to stand at room temperature. However, the kneaded product is cooled as it is by immersing it in water at 5 to 60 ° C. as it is. Thereby, the morphology in the melt-kneaded material is effectively maintained.

  The conductive resin composition thus obtained has a melt viscosity in the range of 10 to 2000 [Pa · s] at 300 ° C., but 10 to 300 [Pa · s] particularly for injection molding. Can be suitably used, and for film or sheet applications, those having a viscosity of 300 to 2000 [Pa · s] can be suitably used.

<Molded body>
The conductive resin composition of the present invention can be molded into various parts and members by known and commonly used molding methods such as injection molding, compression molding, extrusion molding, and hollow molding. For example, connectors, Electrical / electronic parts such as sockets, relay parts, coil bobbins, optical pickups, oscillators, printed wiring boards, computer-related parts; IC manufacturing parts such as IC trays, wafer carriers; VTRs, televisions, irons, air conditioners, Home appliance parts such as stereos, vacuum cleaners, refrigerators, rice cookers, and luminaires; luminaire parts such as lamp reflectors and lamp holders; acoustic product parts such as compact discs, laser discs (registered trademark), and speakers; Communication equipment parts such as optical cable ferrules, telephone parts, facsimile parts, modems, etc .; Copier-related parts such as heater holders; machine parts such as impellers, fans, gears, gears, bearings, motor parts and cases; mechanism parts for automobiles, engine parts, engine room parts, electrical parts, interior parts, etc. Automobile parts; Cooking equipment such as microwave cooking pots, heat-resistant dishes, etc .; Insulation such as flooring and walls, soundproofing materials, supporting materials such as beams and pillars, roofing materials, and other building materials or civil engineering Materials: Aircraft parts, spacecraft parts, nuclear facility radiation facility members, marine facility members, cleaning jigs, optical equipment parts, valves, pipes, nozzles, filters, membranes, medical equipment parts, etc. Examples include medical materials, sensor parts, sanitary equipment, sports equipment, and leisure equipment.

<Manufacture of electrophotographic transfer belt>
The pellet of the resin composition obtained by cooling and pulverizing as desired achieves uniform dispersion of the conductive material in the resin composition and becomes a thermoplastic resin composition having excellent conductivity. In order to form the desired electrophotographic transfer belt, this is further subjected to a molding machine, and various known molding methods such as an extrusion molding method, an injection molding method, a compression molding method, a blow molding method, and an injection compression molding method are used. To obtain a sheet or film (molding process). The shape of the sheet or film is not particularly limited, and examples thereof include a seamless ring shape obtained by extrusion molding in a ring shape and a sheet shape processed into a cylinder. The transfer belt of the present invention preferably has a seamless annular shape.

  Next, by cooling the formed belt-shaped product, an electrophotographic transfer belt excellent in conductivity can be obtained, in which the dispersed form of the conductive material is effectively maintained. Cooling may be performed by allowing the belt-shaped article to stand at room temperature, but it is preferable that the belt-shaped article is rapidly cooled by being immersed in water at 5 to 60 ° C.

  In addition, although the said additive and a reinforcement | strengthening agent are normally added and mixed when melt-kneading a resin composition, you may add and mix using a side feeder at the shaping | molding process to the belt shape of a resin composition. In particular, an additive with a small blending amount may be added and mixed immediately before the forming step into the belt shape.

  The transfer belt of the present invention is an intermediate transfer belt for once transferring a toner image formed on a photoreceptor onto its surface and further transferring the transferred toner image onto a recording material such as paper. Alternatively, a direct transfer belt that directly adsorbs a toner image formed on the photosensitive member by electrostatically adhering the paper to the paper may be used.

  As the transfer belt of the present invention, the belt made of the resin composition may be used as it is, but the effect of the present invention can be obtained more effectively if only the surface is hardened in order to increase the transfer efficiency. As a method for hardening only the surface, a method of coating an inorganic material is preferable, but the method is not particularly limited. For example, a method by coating as described in “New Development of Sol-Gel Method Application Technology” (CMC Publishing), CVD, PVD, plasma coating, etc. described in “Introduction to Thin Film Materials” (Yuhuabo) Known methods such as a physicochemical method can be employed. The inorganic material coated on the surface is not particularly limited as long as the object of the present invention can be achieved, and an oxide-based material containing Si, Al, and C is particularly preferable in view of physical properties and economy. For example, an amorphous silica thin film, an amorphous alumina thin film, an amorphous silica alumina thin film, an amorphous diamond thin film, etc. are recommended. By coating the belt of the present invention with an inorganic thin film having a hardness higher than that of PPS, not only the friction wear life with the blade is improved, but also the transferability is improved.

  The transfer belt of the present invention can be applied to a transfer belt used in an intermediate transfer type image forming apparatus, particularly a seamless seamless belt. The transfer belt according to the present invention is a monocolor image forming apparatus having only a single color toner in the developing device, Y (yellow), M (magenta), C (cyan), B (black) for one latent image carrier. A full-color image forming apparatus that performs development on a latent image carrier and primary transfer of a toner image to a transfer belt for each color developer, one for each latent image carrier. Tandem-type full-color image forming apparatus in which image forming units for each color equipped with a developing device are arranged in series and each image forming unit performs development on a latent image carrier and primary transfer of a toner image to a transfer belt Can be applied to. By applying the transfer belt of the present invention, it is possible to provide an image forming apparatus capable of suppressing character voids and toner scattering.

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

[Example 1]
Polyphenylene sulfide resin (“MA-520” manufactured by DIC Corporation) melt viscosity V6p at about 300 ° C. about 120 [Pa · s], non-Newton index 0.99, carboxy group content 44 μmol / g, alkali metal salt 9.6 μmol / g ) 3330 parts by mass, polyethersulfone resin (BASF “PES E1010” melt viscosity at 300 ° C. (V6a) of about 4000 [Pa · s]) 370 parts by mass, carbon (“Denka Black” manufactured by Denki Kagaku Kogyo Co., Ltd.) 300 parts by mass were uniformly mixed with a tumbler to obtain a blended material. Thereafter, the blended material was charged into a vented twin-screw extruder “TEX-30” manufactured by Nippon Steel Works, Ltd., resin component discharge rate 15 kg / hr, screw rotation speed 200 (rpm), resin component discharge rate (kg / Hr) and screw rotation speed (rpm) ratio (discharge amount / screw rotation speed) = 0.075 (kg / hr / rpm), maximum torque 40 (A), and melt kneading at a set resin temperature of 310 ° C. A pellet (1) of the resin composition was obtained. The melt viscosity [Pa · s] at 300 ° C. of the resin composition is shown in Table 1.
The obtained pellet (1) of the resin composition was allowed to stand at room temperature for 24 hours, and then formed into a film at a set resin temperature of 310 ° C. using a T-die extruder to produce a conductive film (1) having a thickness of 80 μm.

[Example 2]
A pellet (2) and a conductive film (2) were prepared in the same manner as in Example 1 except that the blending ratio was 1850 parts by mass of the polyphenylene sulfide resin, 1850 parts by mass of the polyether sulfone resin, and 300 g of carbon.

[Comparative Example 1]
3453 parts by mass of polyphenylene sulfide resin (“MA-520” manufactured by DIC Corporation), 247 parts by mass of polyamide resin (“1011FB” manufactured by Ube Industries, Ltd.), 300 parts by mass of carbon (“Denka Black” manufactured by Denki Kagaku Kogyo Co., Ltd.) Were uniformly mixed with a tumbler to obtain a blended material. Thereafter, the blended material was charged into a vented twin-screw extruder “TEX-30” manufactured by Nippon Steel Works, Ltd., resin component discharge rate 15 kg / hr, screw rotation speed 200 rpm, resin component discharge rate (kg / hr) And screw rotation speed (rpm) ratio (discharge amount / screw rotation speed) = 0.075 (kg / hr / rpm), maximum torque 40 (A), and melt kneading at a set resin temperature of 300 ° C. Pellets (3) were obtained. The obtained pellet (3) of the resin composition was allowed to stand at room temperature for 24 hours, and then formed into a film at a set resin temperature of 300 ° C. with a T-die extruder to produce a conductive film (3) having a thickness of 80 [μm].

[Comparative Example 2]
A pellet (4) and a conductive film (4) were produced in the same manner as in Comparative Example 1 except that the obtained resin composition pellet was immediately quenched with water at 24 ° C.

[Comparative Example 3]
Pellets (5), conductive films (as in Example 1) except that (MA-501, manufactured by DIC Corporation, melt viscosity V6p of about 15 [Pa · s] at 300 ° C.) was used as the polyphenylene sulfide resin. 5) was produced.

[Examples 3-4, Comparative Examples 3-5]
Using the conductive films (1) to (5) produced in Examples 1 and 2 and Comparative Examples 1 to 3, the following dispersibility test and conductivity test were performed. The results are shown in Table 1.

(Melt viscosity)
Using a flow tester (Shimadzu Corporation Koka-type flow tester “CFT-500D type”), the temperature / 300 ° C., the load 1.96 MPa, the orifice length / orifice diameter ratio is 10/1. The melt viscosity after holding for 6 minutes was measured using an orifice.

(Dispersibility)
The conductive film was measured with a Keyence microscope (VHX-2000), and the number of aggregated particles per 0.5 cm ^{2 and} the maximum particle size of the aggregated particles were measured.

(Conductivity)
The surface resistance of the conductive film was measured. The measurement was performed at 9 points at intervals of 40 mm in the width direction and the length direction of the test piece with a resistance meter (Hiresta: manufactured by Mitsubishi Chemical Analytech Co., Ltd.).
Test piece: 100 mm (width) x 100 mm (length)

Claims (15)

A conductive resin composition comprising, as essential components, a polyarylene sulfide resin (A), an amorphous polymer (B), and a conductive material (C),
The ratio V6p / V6a between the melt viscosity (V6p) of the polyarylene sulfide resin (A) measured at 300 ° C. and the melt viscosity (V6a) of the amorphous polymer (B) measured at 300 ° C. is 0.005 or more. A conductive resin composition characterized by being in a range. The conductive resin composition according to claim 1, wherein the amorphous polymer (B) has a melt viscosity (V6a) measured at 300 ° C. of 20 to 5000 [Pa · s]. The conductive resin composition according to claim 1, wherein the conductive resin composition has a melt viscosity (V6c) measured at 300 ° C. of 10 to 2000 [Pa · s]. 2. The conductive resin composition according to claim 1, wherein the conductive resin composition has a microphase separation structure in which the amorphous polymer (B) is dispersed in the form of particles using the polyarylene sulfide resin (A) as a matrix. Resin composition. The conductive resin composition according to claim 4, wherein the amorphous polymer (B) dispersed in the form of particles has an average particle size in the range of 1 to 100 [μm]. The conductive resin composition according to claim 4, wherein the conductive material (C) is further dispersed in the amorphous polymer (B) dispersed in the form of particles. The conductive resin composition according to claim 1, wherein the conductive material (C) is a particle having a particle size in the range of 0.005 to 5 μm. The conductive resin composition according to claim 1, wherein the amorphous polymer (B) is a polyether sulfone resin. The conductive resin composition according to claim 1, wherein the conductive material (C) is carbon black. In a ratio that the amorphous polymer (B) is in the range of 10 to 100 parts by mass and the conductive material (C) is in the range of 1 to 30 parts by mass with respect to 100 parts by mass of the polyarylene sulfide resin (A). The conductive resin composition according to claim 1. A molded article obtained by molding the conductive resin composition according to claim 1. A film or sheet obtained by molding the conductive resin composition according to claim 1. An electrophotographic transfer belt obtained by extrusion-molding the conductive resin composition according to claim 1 into a ring shape. An image forming apparatus comprising the electrophotographic transfer belt according to claim 13. A method for producing a conductive resin composition comprising melt-kneading a polyarylene sulfide resin (A), an amorphous polymer (B) and a conductive material (C),
The ratio V6p / V6a between the melt viscosity (V6p) of the polyarylene sulfide resin (A) measured at 300 ° C. and the melt viscosity (V6a) of the amorphous polymer (B) measured at 300 ° C. is 0.005 or more. The manufacturing method of the conductive resin composition characterized by existing in the range.