WO1998023686A1

WO1998023686A1 - Semiconductive resin composition

Info

Publication number: WO1998023686A1
Application number: PCT/JP1997/004353
Authority: WO
Inventors: Hideki Kitamura; Yoshikichi Teramoto; Satoru Matsunaga; Masami Akatsu
Original assignee: Kureha Kagaku Kogyo K.K.
Priority date: 1996-11-29
Filing date: 1997-11-28
Publication date: 1998-06-04
Also published as: CN1245515A; DE19782141T1

Abstract

A semiconductive resin composition comprising 100 parts by weight of a thermoplastic resin having a relative permittivity of 2.5 or above as determined at 1 KHz and 23 °C and 0.01 to 5 parts by weight of a cesium salt having a perfluoroalkyl group.

Description

Description Semiconductive resin composition <Technical field>

The present invention relates to a semiconductive resin composition, and more particularly, to a semiconductive resin composition having an appropriate volume resistivity, a uniform distribution of the volume resistivity, a small variation, and a high voltage repeatedly applied. Also, the present invention relates to a semiconductive resin composition having a small change in volume resistivity, a small dependency of volume resistivity on humidity, and a small amount of fisheye.

The semiconductive resin composition of the present invention has at least a surface layer such as a charge roll, a transfer roll, a development roll, a charge belt, and a charge removal belt in an electrophotographic image forming apparatus. It is suitable as a material to be formed. Further, the semiconductive resin composition of the present invention can be used for applications utilizing semiconductivity, antistatic properties, dust absorption preventing properties, etc., for example, films for packaging electronic parts, wallpapers, 0A equipment exteriors. It is suitable as a material.

In the field of electrical and electronic equipment, resin materials capable of precisely controlling static electricity are required. For example, in an image forming apparatus such as an electrophotographic copying machine, a facsimile machine, a laser beam printer, etc., the charging, exposure, development, transfer, fixing, and static elimination steps are performed. An image is formed. In each of these steps, it is necessary to precisely control static electricity.

In an electrophotographic image forming apparatus, generally, (1) a step of uniformly and uniformly charging the surface of a photoconductor drum, and (2) a photoconductor drum by exposure. A process of forming an electrostatic latent image (electrostatic image) on the surface, ③ a process of developing the electrostatic latent image into a visible image (toner image) with a developer (toner), ④ a photoreceptor drum A step of transferring toner onto a transfer material (for example, transfer paper), a fixing step of fusing the toner on the transfer material by applying pressure and heating, and a step of cleaning toner remaining on the photoconductor drum. An image is formed by each step such as a cleaning step.

The charging roll (or belt), developing roll, toner layer thickness regulation blade, transfer roll (or belt), etc. installed in such an image forming apparatus. includes this the surface layer is a semi-conductive, in particular, the this with ^{^{1 0 5 ~ 1 0 U Q}} m approximately of the volume resistivity is required. For example, in a charging method using a charging roll, a charge is applied directly to the surface of the photoconductor drum by bringing the charging port to which a voltage is applied into contact with the photoconductor drum, so that the surface is uniformly and uniformly charged. Let me. In a developing method using a developing roller, the frictional force between the developing roll and the toner supply roll causes the toner to adhere to the surface of the developing roll in a charged state, and the toner is regulated in a toner layer thickness regulating blade. Then, the electrostatic latent image on the surface of the photoreceptor drum is developed by flying with an electric attraction force. In the transfer method using a transfer port, an electric field is generated by applying a voltage having a polarity opposite to that of the toner to the transfer port, and the toner on the photoreceptor is transferred onto the transfer material by the electrostatic force of the electric field. Let me.

Therefore, each member such as a charging roll in an image forming apparatus is required to be semiconductive having a low volume resistivity within an appropriate range. The volume resistivity needs to be uniform in distribution, and if the volume resistivity is different in place, a high-quality image cannot be obtained. For example, if the distribution of the volume resistivity of the charging roll is not uniform, the photosensitive drum surface cannot be charged uniformly and uniformly, and the Quality degrades. In addition, a high voltage is repeatedly applied to these members, and if the volume resistivity fluctuates significantly, high-quality images cannot be stably obtained. If the volume resistivity of these members fluctuates significantly due to changes in humidity or temperature, it is still impossible to obtain high quality images stably. It is possible to cope with changes in temperature by warming the equipment, but it is difficult to cope with changes in humidity under normal operating conditions.

In addition, the exterior materials and parts of the 0A equipment made of polymer materials absorb dust and toner, etc., causing damage to the appearance and failure. Film containers for packaging electronic components such as IC and LSI are required to have antistatic properties. In order to provide dust-prevention and anti-static properties, it is effective to reduce the electrical resistivity of polymer materials and their molded products.

Conventionally, methods for lowering the electrical resistivity of a polymer material or its molded article include (1) a method of applying an organic antistatic agent to the surface of the molded article, and (2) a method of applying an organic (3) kneading a conductive filler such as carbon black or metal powder into a polymer material, and (4) kneading an electrolyte into a polymer material Is known o

However, the method (1) cannot expect a long-term antistatic effect because the antistatic agent easily falls off by wiping or cleaning the molded product surface. In the method (2), a surfactant or a hydrophilic resin is used as the organic antistatic agent. The method using a surfactant employs a mechanism that imparts antistatic properties by blowing out the surfactant from the surface of the molded product. Changes in electrical resistivity and antistatic properties It changes. In a method using a hydrophilic resin, a large amount of the hydrophilic resin must be blended in order to obtain a desired antistatic effect, so that it is difficult to maintain the original good physical properties of the polymer material. In addition, there is a problem that the electrical resistivity and the antistatic property are largely dependent on humidity.

The method (3) has been adopted in many fields. For example, a charging roll is formed by coating a core metal with a semiconductive high molecular composite material (composition) obtained by kneading a conductive filler into a polymer material. However, composite materials in which a conductive filler is dispersed in a polymer material to be semiconductive generally have a very non-uniform volume resistivity distribution, and the variation is often large. However, this is several orders of magnitude, and there is a problem in practical performance. In addition, a composite material in which a conductive filler is dispersed in a polymer material generally does not have a sufficient withstand voltage, and is not necessarily suitable for applications in which a high voltage is repeatedly applied. In addition, in order to achieve the required level of semi-conductivity using a conductive filler, it is necessary to increase the filling amount thereof. The problem is that the mechanical strength is reduced or the hardness is too high. In many cases, a polymer composite material in which a conductive filler is dispersed is colored by a conductive filler such as a conductive black. It is unsuitable for use in applications such as device exterior materials and wallpaper.

The (4) In the method of, chloride Li Chiumu Ya chloride force in a polymer material Li ©-time of any Al force Li metal salt (electrolyte) kneading the, by Ri electricity to the metallic ions such as L i + and ^Κ τ The resistivity is reduced (Japanese Patent Publication No. 63-140177). The inorganic metal salt used as the alkali metal salt in this method has a problem that the fishy eye due to agglomerates or the like is liable to be generated due to poor affinity for the resin. Was. This aggregate is converted to resin Increasing the kneading temperature or increasing the kneading time in order to dissolve it into the solution did not solve the problem because the resin or inorganic metal salt would decompose and impaired the practical mechanical properties and appearance. . In the case of a deliquescent metal salt such as Li salt, if filled in a large amount, the polymer composite material becomes hygroscopic, and the volume resistivity increases due to changes in humidity. There is a problem that the surface of the molded article becomes sticky due to the deliquescence of the metal salt that has been changed or pre-doped out.

On the other hand, fluoroplastics such as polyolefin vinylidene (PVDF) have excellent heat resistance, weather resistance, chemical resistance, solvent resistance, ozone resistance, stain resistance, and non-adhesive properties. ing. In an electrophotographic image forming apparatus, a member that comes into contact with a toner such as a charging port or a developing roll has a phenomenon that the toner fuses and forms a film (filming phenomenon). This phenomenon is unlikely to occur in a member made of fluororesin, although it is likely to occur. Therefore, fluororesins are expected to be suitable for use in electrophotographic image forming apparatuses, for example, for charging rolls, charging belts, developing rolls, transfer rolls, and the like. .

However, fluororesins such as PVDF, like many polymer materials, have high electrical resistivity and are not semiconductive. Fluorine resin is easily charged by friction. Fluororesin members absorb dust and toner, etc., and can damage the appearance or cause a failure. Conventionally, fluororesin has been used for the surface layer of the fixing roll (heating port) in image forming equipment because it is non-adhesive and has excellent toner release properties. There were many problems to be solved when used as a charging member such as a mouthpiece.

In order to reduce the electric resistivity of a fluororesin such as PVDF to make it semiconductive, the above-mentioned methods (1) to (4) can be applied. Only However, applying these conventional methods to fluororesin has the following problems in addition to the above-mentioned problems.

Since fluororesin has excellent non-adhesiveness, even if an organic antistatic agent is applied to the fluororesin molded article by the method (1), the fluororesin easily falls off. According to the method (2), when a surfactant is kneaded into a fluororesin to form a composite material, the surfactant bleeds out, which is an advantage of the fluororesin. And damages other members that come into contact with the fluororesin molded product, and adversely affects the charging characteristics of the toner. In the method of kneading a hydrophilic resin into a fluororesin, the electric resistivity cannot be sufficiently reduced unless a large amount of the hydrophilic resin is added, so that the ozone resistance and the solvent resistance decrease.

According to the method (3), the composite material in which the conductive filler is dispersed in the fluororesin has a small surface energy of the fluororesin, so that the composite material can be formed by applying a high voltage. There is a problem that the conductive filler moves easily in the resin, and as a result, the volume resistivity fluctuates, and the distribution of the distribution becomes severe.

According to the method (4), for example, it has long been known that PVDF is a good conductor of ion (for example, Japanese Patent Application Laid-Open Nos. — Japanese Patent Application Laid-Open No. 110658/1994, Japanese Patent Application Laid-Open No. 51-111133 / Japanese Patent Application Laid-Open No. 54-127,772) It is expected to be effective for imparting conductivity. However, when a resin composition obtained by kneading an inorganic metal salt such as lithium chloride or chlorinated lime with a fluororesin is used as a charging member such as a charging roll or belt, a high voltage is repeatedly applied. Doing so has the disadvantage of increasing the volume resistivity. This phenomenon occurs when a high voltage is applied, and metal ions such as L i ^τ and K + gradually move to the negative electrode side. It is presumed that this is due to uneven distribution of metal ions in the charging member.

Conventionally, a method of adding lithium perchlorate and a low molecular weight organic solvent as a third component to PVDF has been proposed as a method of reducing the amount of metal salt added and lowering the volume resistivity. (Japanese Unexamined Patent Publication No. Sho 61-72061, Japanese Unexamined Patent Publication No. Sho 61-62545). However, this method cannot satisfy the appearance and the mechanical strength of the molded product, and the stickiness of the surface is further deteriorated by the bleed out of the organic solvent.

Also, a method has been proposed in which as a third component, a hygroscopic ion good solvent solvent resin such as a polyalkylenoxy dopehalohydrin polymer is added (Japanese Unexamined Patent Publication No. Hei 7-2). No. 4,739,977, Japanese Unexamined Patent Application Publication No. H8-165,955, and Japanese Unexamined Patent Application Publication No. H8-176,839). However, in this method, since a hygroscopic resin is added, the volume resistivity is largely dependent on humidity, and the pollution resistance and the ozone resistance are deteriorated.

An object of the present invention, 1 0 ⁵ have a ~ 1 Omicron ^ Omega moderate volume resistivity of about Paiiota, and distribution of the volume resistivity uniform dispersion is rather small, less off Lee Tsu Shi Yuai semiconductive An object of the present invention is to provide a conductive resin composition.

Another object of the present invention, 1 0 ⁵ to 1 has a 0 ^eta Omega m about a volume resistivity rather small variations in volume resistivity, change of the volume resistivity even after repeated application of a high voltage low Another object of the present invention is to provide a semiconductive resin composition having a small humidity dependence of the volume resistivity and having a small fisheye. The inventors of the present invention have conducted intensive studies to overcome the problems of the prior art, and found that a thermoplastic resin having a relative dielectric constant of 2.5 or more measured at 1 KHz and 23 ° C was used as an electrolyte. Perfluoroalkyl sulfonate When a perfluoroalkyl group-containing cesium salt such as lime is blended, the above-mentioned characteristics are remarkable as compared with the case where a conventional inorganic metal salt such as lithium chloride and chlorinated lime is blended. It has been found that an excellent semiconductive resin composition can be obtained.

The perfluoroalkyl group-containing cesium salt used in the present invention is dissolved in a thermoplastic resin having a relative dielectric constant of 2.5 or more measured at lk Hz and 23 ° C., and has a glass transition temperature of the resin or higher. It is a compound (electrolyte) that exhibits ionic conductivity at a temperature of. When the perfluoroalkyl group-containing cesium salt is added to the thermoplastic resin, it is dispersed uniformly, and at least a part of the cesium salt is ionized into cations and anions in the resin. It is estimated that

The resin composition of the present invention in which a perfluoroalkyl group-containing cesium salt is blended in a predetermined ratio has the following features: (1) has a volume resistivity in a semiconductive region, and (2) has a uniform and uniform distribution of volume resistivity. Small, ③ little change in volume resistivity even after repeated application of high voltage, ④ little humidity dependency of volume resistivity, ⑤ few fish eyes, 少ない little door-to-door It has the following characteristics.

No ,. These characteristics brought about by the addition of the fluorinated alkyl group-containing cesium salt are unexpected and remarkable, and the thermoplastic resin having a specific specific dielectric constant and the perfluoroalkyl group-containing cesium salt are used. The remarkable effects of the combination with shim salts are clearly shown.

The present invention is effective for imparting semiconductivity to a thermoplastic resin having a relative dielectric constant of 2.5 or more. Among them, a fluororesin and a vinylidene among the fluororesins are particularly preferable. It is particularly effective when a resin is used. The present invention has been completed based on these findings.

Thus, according to the present invention, the relative dielectric constant measured at 1 KHz and 23 ° C. A semiconductive resin composition containing 0.01 to 5 parts by weight of a perfluoroalkyl-containing cesium salt per 100 parts by weight of a thermoplastic resin having a ratio of 2.5 or more is provided. Is done. <Best mode for carrying out the invention>

(Thermoplastic resin)

The thermoplastic resin used in the present invention has a relative dielectric constant at lk Hz, 23 of 2.5 or more, preferably 3 or more, more preferably 4 or more. A thermoplastic resin having a relative dielectric constant of less than 2.5 has poor compatibility with a perfluoroalkyl group-containing cesium salt, making it difficult to dissolve the cesium salt in the resin. However, it is difficult to obtain a semiconductive resin composition having an appropriate volume resistivity and having a small variation in volume resistivity.

As the thermoplastic resin having a relative dielectric constant of 2.5 or more at lk Hz and 23 ° C, there are fluorocarbon resin, polyamide resin, vinyl chloride resin, and polycarbonate resin. And polyester resins (polyethylene terephthalate, etc.). Of these, fluorine resin is more preferred.

Examples of the fluororesin having a relative dielectric constant of 2.5 or more at 23.degree. C. at lk Hz include, for example, Fidani vinylidene resin, Futidani vinyl resin, and ethylene — Examples include tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), and ethylene monocyclotrifluoroethylene (ECTFE). . Among these fluororesins, vinylidene fluoride resins are particularly preferred in view of the remarkable effects of the moldability and semiconductivity.

Examples of the vinylidene fluoride resin include polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymer, and fluorine resin. Nitridentate tetrafluoroethylene copolymer, futsudani vinylidenetetrafluoroethylene copolymer, and hexafluoropropylene copolymer. These Fusidani vinylidene resins can be used alone or in combination of two or more.

Among vinylidene fluoride resins, from the viewpoints of stain resistance, ozone resistance and solvent resistance, PVDF which is a homopolymer of polyvinylidene fluoride is preferred. From the viewpoints of flexibility and tear strength, it is preferable to use fusidani vinylidene polymer mainly composed of vinylidene fluoride alone or blended with PVDF. For the purpose of improving the adhesiveness, vinylidene fluoride having a functional group introduced is also preferably used. The vinylidene fluoride resin may be used by blending it with another fluorine resin. Further, a thermoplastic resin other than the fluorocarbon resin may be blended as long as the contamination resistance, ozone resistance and chemical resistance of the vinylidene fluoride resin are not significantly reduced.

(Perfluoroalkyl group-containing cesium salt)

In the present invention, in order to reduce the electrical resistance (volume resistivity) of the thermoplastic resin having the predetermined relative dielectric constant, such as a fluororesin, to make it semiconductive, the electrolyte is made of perfluoro. Contains cesium salt containing alkyl group.

The perfluoroalkyl group-containing cesium salt used in the present invention is a compound containing a perfluoroalkyl group and cesium in a molecule, and is an organic salt exhibiting properties as an electrolyte. It is. Examples of the cesium salt containing a perfluoroalkyl group include cesium perfluoroalkyl sulfonate, ⁰ -fluoroalkyl cesium oleate, and monofluoroalkyl carbonyl. Cesium phosphate can be mentioned.

As a fluorinated alkyl group-containing cesium salt, the number of carbon atoms is Usually, a compound containing a 5,200, preferably 5L5, more preferably 510, perfluoroalkyl group is desirable. ,. (I) If the number of carbon atoms in the fluoroalkyl group is too small, the perfluoroalkyl group-containing cesium salt becomes brittle, and if it is too large, the effect of imparting conductivity is reduced. These perfluoroalkyl group-containing cesium salts can be used alone or in combination of two or more. In order to balance the effect of imparting conductivity with the suppression of bleeding out, two or more kinds of cesium salts containing a perfluoroalkyl group having different molecular weights may be used in combination. These perfluoroalkyl group-containing cesium salts have excellent compatibility with thermoplastic resins having a specific dielectric constant of 2.5 or more at 1 kHz 23 ° C, and have a high volume resistivity. The effect of reducing the rate is good, and the resin is not colored. Among these fluoroalkyl group-containing cesium salts, cesium perfluoroalkylsulfonate is particularly preferred.

The mixing ratio of the perfluoroalkyl group-containing cesium salt is 0.015 parts by weight, preferably 0.051 parts by weight, based on 100 parts by weight of the thermoplastic resin. More preferably, it is in the range of 0.10.5 parts by weight. If the mixing ratio of the perfluoroalkyl group-containing cesium salt is too small, the effect of reducing the volume resistivity is small, and if it is too large, the cesium-containing electrolyte may bleed out or be molded. May become cloudy. In the case of a fluororesin such as vinylidene fluoride resin, if the mixing ratio of the fluoridyl group-containing cesium salt is too large, the precipitation of agglomerates increases, and the type of the resin and Decomposition or coloring may occur depending on the processing conditions. When the perfluoroalkyl group-containing cesium salt is cesium perfluoroalkylsulfonate, a sufficient action and effect can be obtained even with a mixing ratio of about 0.10.5 parts by weight. Can get Wear.

(Other additives)

Various additives can be added to the semiconductive resin composition of the present invention as needed.

Examples of additives include talc, myric, silica, alumina, titanium oxide, zinc oxide, iron oxide, aluminum hydroxide, magnesium hydroxide, graphite, and organic metals. Powdered fillers such as salts and metal oxides; fiber fillers such as glass fibers; and the like. These fillers are used within a range not to impair the purpose of the present invention.

General-purpose additives such as antioxidants, lubricants, plasticizers, organic pigments, inorganic pigments, ultraviolet absorbers, surfactants, inorganic acids, organic acids, pH adjusters, cross-linking agents, and cutting agents Can be used as long as the object of the present invention is not hindered.

(Semiconductive resin composition)

The semiconductive resin composition of the present invention can be obtained by uniformly dispersing a perfluoroalkyl group-containing cesium salt in a thermoplastic resin having a relative dielectric constant of 2.5 or more measured at 130 ° C. and 23 ° C. It can be obtained by dispersing. The fact that the perfluoroalkyl group-containing cesium salt is uniformly dispersed in the thermoplastic resin is determined by whether or not a resin composition having a desired volume resistivity of the semiconductive region is obtained. It can be.

According to the present invention, the volume resistivity is typically between 10 ^J and 10 ^U Qm, preferably between 10 'and 10 ^U Qm, and more preferably between 10 ^o and 10 ^U Q It is possible to obtain a semiconductive resin composition in the range of m.

The method of mixing the components is not particularly limited. As a preferable mixing method, for example, a perfluoroalkyl group-containing cesium salt is dissolved in a mixed solvent of water and a water-soluble solvent, and a resin powder is added thereto. Then, after mixing with a mixer such as a mixer, there is a method of drying (in some cases, drying under reduced pressure), and melt-extruding the obtained dried product to form a pellet.

For example, when a vinylidene fluoride resin is used as the thermoplastic resin, a cesium salt containing a perfluoroalkyl group is added to warm water containing about 5% by volume of acetone. Dissolving, adding a resin powder to the mixture, mixing, drying, and then pelletizing the dried product by a melt extrusion method. When the perfluoroalkyl group-containing cesium salt is cesium perfluoroalkylsulfonate, the same effect can be obtained by dissolving in water and directly by dry blending with the resin. In this case, it is preferable to pulverize cesium perfluoroalkylsulfonate into a fine powder and then mix it with the resin in order to make the mixing as uniform as possible.

Various molding methods such as a melt extrusion method, an injection molding method, a solution casting method, and a coating method can be applied to the molding of the semiconductive resin composition. It is also possible to prepare a master pellet containing a high concentration of cesium salt containing a fluoroalkyl group and dilute it with resin as required during molding before processing. .

When extruding the semiconductive resin composition of the present invention into a sheet or a seamless belt, a continuous extrusion method is preferably employed. A desirable continuous extrusion molding method for a sheet is to extrude a molten resin composition directly from a lip using a single-screw or twin-screw extruder and a T-die. In addition, a method of cooling and solidifying while adhering to the cooling drum with an air knife or the like can be cited. In particular, when using vinylidene fluoride resin, it is desirable to control the cooling temperature within the range of 0 to 100 ° C. Desired continuous melt extrusion of seamless belt For this purpose, a single-screw or two-screw screw extruder and a spiral ring die are used to extrude directly from the die lip to the internal cooling mandrel system. Thus, it is possible to cite a method of taking out while controlling the inner diameter.

In order to form a roll-shaped molded product such as a charging roll using the semiconductive resin composition of the present invention, the semiconductive resin composition is formed into a tube in advance, and then the cored metal is formed. Coating directly or through another layer (for example, another resin layer, a elastomer layer, a primer layer, etc.), or applying the semiconductive resin composition directly on the core metal or another layer. For example, a method of coating by a coating method via a coating method is employed.

Films, sheets, tubes, filaments, and other various molded articles can be obtained by applying a common melt molding method such as injection molding or extrusion molding to the semiconductive resin composition of the present invention. Can be obtained by: The semiconductive resin composition of the present invention can be applied to various application fields requiring antistatic properties, antistatic properties, static elimination properties, semiconductivity, and the like. The semiconductive resin composition of the present invention may be used alone, or may be used in combination with another resin, an elastomer, a metal, or the like, if necessary. For example, a layer made of the semiconductive resin composition of the present invention and another resin layer can be combined to form a laminated sheet. Although all of the various molded articles may be molded with the semiconductive resin composition of the present invention, to impart semiconductivity to the surface of the molded article, only the surface layer of the semiconductive resin of the present invention is used. It may be formed of a composition.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The methods for measuring physical properties are as follows.

(1) Thickness

The thickness of the molded product was measured using a dial gauge thickness gauge (trade name “DG-911” manufactured by Ono Sokki Co., Ltd.).

(2) Volume resistivity

The volume resistivity was measured according to JIS K6911. More specifically, a load is applied to a resinity cell having a ring-shaped electrode (HP 16008B, manufactured by Hulett Packard Co., Ltd.). The sample was sandwiched by kgf, and the volume resistivity was measured when a voltage of 1 kV was applied between the inner electrode and the counter electrode for 1 minute in the thickness direction. The outer diameter of the inner electrode is 26.0 mm, the inner diameter of the outer counter electrode is 38.0 mm, and the outer diameter of the counter electrode is 40.0 mm. The volume resistivity was determined with a measuring device (trade name “HP433A high resistance meter”) manufactured by Hulett Packard Co., Ltd. The sample was left in an atmosphere at a room temperature of 23 ° C and a humidity of 50% for at least one day before measurement, and then measured in this environment.

(3) Average value calculation

The above thickness and volume resistivity measurements were made on 20 sheets of arbitrarily selected sheet-like samples, and the arithmetic mean value was obtained for the thickness, and the maximum and minimum values were obtained for the volume resistivity. The values and the arithmetic mean were determined.

(4) Volume resistivity under repeated voltage application

The measurement was performed in the same manner as the above-described method of measuring the volume resistivity. However, the cycle of voltage application time of 100 V for 10 seconds and non-voltage application time of 100 seconds is one cycle, and the cycle is repeated up to 300 times, and the volume resistivity at each voltage application Was measured. The application and non-application of the voltage are controlled by a personal computer. Pew evening controlled.

(5) Humidity dependence of volume resistivity

The sample was placed in a thermo-hygrostat at 23 ° C at a relative humidity of 30%, 50%, 70% and 90% [LH301-M, manufactured by Nagano Chemical Machinery Co., Ltd. ]] For 24 hours, and the volume resistivity was measured by the method described above. However, a voltage of 10 V instead of 1 kV was applied between the inner electrode and the counter electrode for 1 minute in the thickness direction.

(6) Bleed out

The samples were left for 30 days in an environment at a temperature of 23 ° C and a relative humidity of 50%, and then visually inspected and touched to check for the presence of additive bleed-out.

(7) Fish eye

The sheet-like sample used for measuring the volume resistivity was visually inspected for the presence or absence of fisheye.

[Example 1]

° - Furuo Roo click data Nsuruho phosphate force Li ©-time; the [Dainippon I Nki chemical E Industry Co., Ltd. under the trade name "F 1 1 0" C ₈ F ₁₇ S 0 ₃ K] 5 3. 8 g The solution A was dissolved in a mixture of 700 cc of Aceton Z water (mixing ratio = 70 cc / 630 cc) at 50 ° C to obtain a solution A. On the other hand, 20 g of cesium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 300 cc of water (50 ° C.) to obtain a solution B. Solution A and solution B were mixed and stirred to precipitate a white precipitate. After removing water-soluble components from the precipitate by filtration, the precipitate was washed with 300 cc of pure water, filtered, and then dried under reduced pressure at 90 ° C to obtain perfluorooctane sulfonate. cesium _{_{_{[C 8 F 17 S 0 3 C}}} s ] to obtain about 5 0 g. Dissolve cesium monofluorooctanesulfonate (hereinafter abbreviated as “PFSC s”) in hot water at about 90 ° C so that the composition ratio shown in Table 1 is obtained. After unraveling, the mixture was gradually cooled to a temperature of 40 to 50 ° C., and then, an amount of acetone having an acetate concentration of 5% by volume was added. In this solution, Porifutsu-Dani Vinylidene (PVDF) [produced by Kureha Chemical Industry Co., Ltd., product name "# 850"; = 10.0]. Using a mixer [trade name “Super Mixer” manufactured by Kawada Manufacturing Co., Ltd.], the mixture was stirred and mixed at a rotation speed of 100 rpm for about 5 minutes. The mixing ratio of the resin to the solvent was 120 cc of warm water at 40 to 50 ° C and 10 cc of acetate per 100 g of the resin powder.

The obtained mixture was dried in an oven at 100 ° C. for 24 hours, and then dried under reduced pressure at 90 ° C. for 5 hours. Then, a single-screw screw extruder [Pula Giken ( And a diameter of about 3 mm at a die temperature of 230.

Using a single screw extruder (manufactured by Bragiken Co., Ltd.), the pelletized raw material is used to prepare a lip outer diameter (diameter) of 50 mm0 and a lip clearance. It was supplied to a spiral annular die having a diameter of 1 mm and a die temperature of 230 ° C., and was extruded from the lip of the die into an annular molten film immediately below. While controlling the inner diameter of the extruded annular molten film by inner diameter siding (40 ° C.), the molten film was pulled down directly under a nipple. The obtained annular film was cut into a piece having a length of about 400 mm at a right angle to the flow axis direction, and then cut into a sheet. The thickness of the obtained sheet was 150 μm.

A sample was prepared using the sheet thus obtained, and the volume resistivity and the like were measured. Table 1 shows the results.

[Examples 2 and 3]

Example 1 was repeated in the same manner as in Example 1 except that the mixing ratio of PFSCs was changed as shown in Table 1. Table 1 shows the results Shown in

[Example 4]

In Example 1, in place of PVDF, Futizani vinylidene-hexafluoropropylene copolymer (hereinafter abbreviated as “VDFP”) [manufactured by Kureha Chemical Industry Co., Ltd .; 3 0 0 ”; 1 Κ Η, the relative permittivity at 23 = £ '= 9.8], and the mixing ratio of PFSC s was changed as shown in Table 1. Performed as in Example 1. Table 1 shows the results.

[Comparative Examples 1 to 3]

In Example 1, PFSCs was replaced by inorganic metal salts such as cesium chloride (CsC1), lithium chloride (LiC1) or potassium chloride (KC1). ) Was used in the same manner as in Example 1 except that each of the compounding ratios shown in Table 1 was used. Table 1 shows the results.

[Comparative Examples 4 to 6]

In Example 1, in place of the PFSC s, Roh, ⁰ - Furuo Roo click data down sulfonic acid force Riumu [Dainippon Inki Chemical Industry Co., Ltd. under the trade name "F 1 1 _0";? C ₈ F ₁ S 0 ₃ K] (hereinafter, "PFSK" for short) or per Furuoro Okuda Nsuruho Nsanri Ji U beam [Dainippon Lee Nki chemical Co., Ltd., trade name "F 1 1 6"; C ₈ F ₁₇ SO. L i] (hereinafter, abbreviated as “PFSL i”) was used in the same manner as in Example 1 except that each mixing ratio shown in Table 1 was used. Table 1 shows the results. oo cn m

Mouth π Volume resistivity

[Ω m]

CO a Sure average value Maximum value Minimum value Presence of a / b Type Copies Type Copies

vl doo (a) (vb) (ratio)

Example 1 \ Ur 1 An

U r Γ S S S U.DU 1.5 x 10 ⁹ Cv 1 Λ9 1 丄. N1! X 1 l Π i9 2.5 None rr ¾ii Example 2 Γ V Ur 丄 1 ππ rr S 2.0 x 10 ⁹ 5. X lU 1.0 X 丄 u 2.8 None

| M

1 l ¹ Π

v_ / I 0 om 2.8 x 10 ⁹ .nyJ

rr Example 3 V _L inn y in ⁹ 1 * Q ym ⁹ 2.6 None

1 Example 4 VDFP 100 PFSCs 0.30 4.8 x 10 ⁹ 1.2 x 10 ¹⁰ 3.7 x 10 ⁹ 3.3 None

\

i Comparative example 1 PVDF 10 addition 0 CsCl 0.10 1.5 x 10 ¹⁰ 2.0 x 10 ¹⁰ 9.2 x 10 ⁹ 2.2 Yes

> \ '

/ Comparative Example 2 PVDF 100 LiCl 0.10 1.1 x 10 ¹⁰ 3.8 x 10 ¹⁰ 8.7 x 10 ⁹ 4.4 Yes

i μπ Comparative example 3 PVDF 100 KC1 0.10 4.4 x 10 ¹⁰ 9.4 x 10 ¹⁰ 3.4 x 10 ¹⁰ 2.8 Yes o

Comparative Example 4 PVDF 100 PFSK 0.10 1.8 x 10 ¹⁰ 3.3 x 10 ¹⁰ 1.4 x 10 ¹⁰ 2.4 None T cv

Comparative Example 5 PVDF 100 PFSK 0.30 1.1 x 10 ¹⁰ 2.5 x 10 ¹⁰ 8.1 x 10 ⁹ 3.1 None a H Comparative Example 6 PVDF 100 PFSLi 0.30 1.3 x 10 ¹⁰ 2.2 x 10 ¹⁰ 9.3 x 10 ⁹ 2.4

鰣 None a

Greens

V body

,

Polymer [Kureha Chemical Industry Co., Ltd., product name "# 2300", relative permittivity ε '= 9.8

(3) PFSCSs. C-Fluorooctane sulphonate

(4) PFSK: Fluorooctane sulphonic acid [trade name "F110" manufactured by Dainippon Inki Chemical Industry Co., Ltd.]

(5) PFSLi—Fluorooctanesulfonate [F1116, manufactured by Dainippon Ink & Chemicals, Inc.]

As is evident from the results in Table 1, the use of cesium monofluorene anolequinolenoslenofonate has an appropriate volume resistivity and a uniform and uniform distribution of volume resistivity. It can be seen that a semiconductive resin composition having a small stick can be obtained (Example 14). In addition, the semiconductive resin composition of Example 14 had no fisheye and no additive pre-drain.

In contrast, when cesium chloride, an inorganic metal salt, is used, a semiconductive resin composition having a uniform volume resistivity distribution and a small variation can be obtained, but the effect of reducing the volume resistivity is obtained. And the fish eyes are observed (Comparative Example 1). When lithium chloride (Comparative Example 2) is used, a resin composition having a large variation in volume resistivity distribution can be obtained, and when chloride chloride (Comparative Example 3) is used, the volume resistivity can be reduced. Small reduction effect. In addition, fishy eyes were observed in all of the resin compositions (Comparative Example 23) containing these inorganic metal salts (LiC1KC1). Further, in the resin composition containing lithium chloride (Comparative Example 2), bleed out was confirmed.

In addition, although an organic metal salt containing a perfluoroalkyl group, the use of a potassium salt (Comparative Example 45) or a lithium salt (Comparative Example 6) can reduce the volume resistivity. Is small. [Example 5, and Comparative Examples 7 to 10]

In the same manner as in Example 1, samples having the components and composition ratios shown in Table 2 were prepared. For each sample, the volume resistivity during repeated voltage application was measured, and the ratio of the volume resistivity in the 300th cycle to the volume resistivity in the first cycle was calculated. Table 2 shows the results.

IN: t

o J1 o

Table 2 Dependence of volume resistivity on the number of times of voltage application Fluororesin

[Ω m]

Voltage application times

Copies Type sfe Copies

1 5 10 100 Example 5 PVDF 100 PFSCs 0.30 3.41 X 10 ⁹ 3.45 X 10 ⁹ 3.49 X 10 ⁹ 3.54 X 10 ⁹ Comparative Example 7 PVDF 100 CsCl 0.30 5.18 X 10 ⁹ 5.25 X 10 ⁹ 5.30 X 10 ⁹ 5.67 X 10 ⁹ Comparative Example 8 PVDF 100 LiCl 0.30 5.83 X 10 ⁹ 8.10 X 10 ⁹ 9.48 X 10 ⁹ 1.55 X 10 ¹⁰ Comparative Example 9 PVDF 100 KC1 0.30 2.31 X 10 ¹⁰ 2.73 X 10 ¹⁰ 2.84 X 10 ¹⁰ 2.90 X 10 ¹⁰ Comparative Example 10 PVDF 100 PFSK 0.30 2.10 X 10 ¹⁰ 2.14 X 10 ¹⁰ 2.18 X 10 ¹⁰ 2.34 X 10 ¹⁰

(Footnote)

(1) PVDF: vinylidene fluoride [Kureha Chemical Industry Co., Ltd., product name "# 850", relative permittivity = 10.0]

(2) PFSCS. C-Fluorooctane sulphonate

(3) PFSK: (I) Fluorooctane sulfonate [F1110, manufactured by Dainippon Ink & Chemicals, Inc.]

As is evident from the results in Table 2, when a perfluoroalkyl group-containing cesium salt is used, a semiconductive resin composition having a small change in volume resistivity even when a high voltage is repeatedly applied can be obtained. (Example 5)

On the other hand, when cesium chloride, an inorganic metal salt, is used, a semiconductive resin composition having a relatively small change in volume resistivity can be obtained even when a high voltage is repeatedly applied. A ash eye was observed (Comparative Example 7). Inorganic metal salt lithium chloride (Comparative Example 8) or chloride

When (Comparative Example 9) was used, the dependency of the volume resistivity on the number of times of voltage application was large, and fish force was also observed in the holding force. — Although it is an organometallic salt containing a phenolic group, the use of a potassium salt has a large dependence of the volume resistivity on the number of times of voltage application and a small effect of reducing the volume resistivity (Comparative Example 1) 0).

[Example 6, and Comparative Examples 11 to 12]

In the same manner as in Example 1, samples having the components and the composition ratios shown in Table 3 were prepared. The humidity dependency of the volume resistivity was measured for each sample. Table 3 shows the results.

(Footnote)

(1) PVDF _: Polyvinylidene fluoride [Kureha Chemical Industry Co., Ltd., product name "# 850", relative permittivity ε '= 10.0]

(2) PFSC s: No. C-Fluorooctane Snorrephonate As is evident from the results in Table 3, the use of perfluoroalkyl group-containing cesium salts results in the temperature dependence of volume resistivity. Small semi-conductive A resin composition is obtained (Example 6). On the other hand, when the inorganic metal salt cesium chloride (Comparative Example 11) was used, the humidity dependency of the volume resistivity was rather large, and lithium chloride (Comparative Example 12) was used. Then, as the humidity increases, the volume resistivity fluctuates rapidly.

According to the present ^{^{invention, 1 0 3 ~ 1 0 1}} 1 Ω have a moderate volume resistivity of the order of m, the distribution of the volume resistivity uniform Barakki is rather small, yet off Lee Tsu push from the eye without half It is possible to provide a conductive resin composition.

The semiconductive resin composition of the present invention is superior in mechanical strength as compared with a conventional method of mixing a conductive filler. Further, a semiconductive resin composition using a fluororesin represented by vinylidene resin has excellent zoning resistance, stain resistance, moldability, and the like, and also has the above-mentioned characteristics. Are better.

Therefore, it is suitable as a material for forming at least a surface layer such as a charging roll, a transfer roll, a developing roll, a charging belt, and a discharging belt in an electrophotographic image forming apparatus. . Further, the semiconductive resin composition of the present invention can be used for applications utilizing semiconductive properties, antistatic properties, dust absorption preventing properties, and the like, for example, films for packaging electronic parts, wallpapers, OA equipment exterior materials, and powders. It is suitable as a tube for transporting a coating material.

Claims

The scope of the claims

With respect to 100 parts by weight of a thermoplastic resin having a relative dielectric constant of 2.5 or more measured at 1.1 KHz and 23 ° C., a perfluoroalkyl group-containing cesium salt of 0.0 was added. A semiconductive resin composition containing 1 to 5 parts by weight.

2. The semiconductive resin composition according to claim 1, wherein the cesium salt containing a perfluoroalkyl group is cesium perfluoroalkylsulfonate.

3. The semiconductive resin composition according to claim 1, wherein the thermoplastic resin is a fluororesin.

4. The semiconductive resin composition according to claim 3, wherein the fluorine resin is a vinylidene fluoride resin.

5. The semiconductive resin composition according to claim 1, comprising 0.05 to 1 part by weight of a perfluoroalkyl group-containing cesium salt based on 100 parts by weight of the thermoplastic resin.

6. The semiconductive resin composition according to claim 1, comprising 0.1 to 0.5 part by weight of a perfluoroalkyl group-containing cesium salt based on 100 parts by weight of the thermoplastic resin.

7. Cesium perfluoroalkylsulfonate has 5 carbon atoms

3. The composition according to claim 2, which contains from 2 to 20 perfluoroalkyl groups. The semiconductive resin composition described above.

8. A method for using the semiconductive resin composition according to any one of claims 1 to 7 for a charging member.

9. The method according to claim 8, wherein the charging member is mounted on an electrophotographic image forming apparatus.