JP2019049065A - Electroconductive polyamide fiber - Google Patents

Abstract

To provide electroconductive polyamide fibers whose resistance value or whose fiber length does not change responding to a temperature/humidity change and whose single fiber thinness is high with small variance; and to provide an electroconductive brush excellent in image printing quality and printing durability.SOLUTION: Electroconductive polyamide fibers of this invention are configured of polyamide, including a dicarboxylic acid unit whose main component is a sebacic acid unit, and electroconductive carbon and have single fiber fineness of 3.0 dtex or less. The content of the electroconductive carbon is 15-35 mass% in the polyamide fibers, and single fiber fineness CV% is 8.0% or less.SELECTED DRAWING: None

Description

  The present invention relates to a conductive polyamide fiber used in a dry copying machine, a facsimile, a printer and the like of an electrophotographic recording system.

  In electrophotographic copiers and the like, the charging unit of an element important for electrostatic latent image format, the cleaning unit for removing the residual toner and charge remaining on the photosensitive member, and the supply unit for applying the charge to the toner are conductive. Many rollers are used. As conductive yarns used for conductive rollers, synthetic fibers such as polyester and polyamide containing cellulose fibers and conductive fine particles are widely used. For example, Patent Document 1 proposes nylon 6 conductive yarns. ing.

  On the other hand, in recent years, electrophotographic copiers and the like are mainly colored and have evolved to high image quality, and there is a demand for upgrading the quality of conductive brushes used in electrophotographic copiers and the like. Nylon 610 conductive yarn has a lower moisture absorption rate than nylon 6 conductive yarn, and is a material that also has the softness characteristic of nylon yarn, so it has recently been attracting attention as a material for conductive brushes. Conductive yarns have been proposed. In addition, toner particles are shifted to smaller particle size along with higher image quality, the conductive brush is also shifted to higher density, and the fibers for conductive brush are shifted to single yarn fineness.

JP, 2009-210655, A JP, 2013-151782, A

  Since the nylon 6 conductive yarn described in Patent Document 1 has high hygroscopicity of the fiber, the resistance value and the fiber length of the conductive yarn change due to the temperature and humidity change. Therefore, when used for a charging brush or toner supply brush, the charge density changes, and when used for a cleaning brush, the toner removal performance changes, etc. There is a problem that affects the print durability involved.

  The nylon 610 conductive yarn described in Patent Document 2 has lower hygroscopicity than nylon 6, so that although a certain effect can be obtained on the resistance value of the conductive yarn and the fiber length change due to the temperature and humidity change, The conductivity of the conductive carbon at the time of melting is poor, and the carbon dispersibility in the fiber is poor. Therefore, in the case of a single fine fiber having a high concentration of conductive carbon, the single yarn fineness is compared with that of nylon 6. The variation is remarkable, processing to a high density brush is difficult, and there is a problem in printing durability when used and printed for a long time.

  Therefore, the present invention is intended to solve the above-mentioned problems, and a conductive polyamide fiber having a small single yarn fineness and a small variation, in which the resistance value and the fiber length of the conductive polyamide fiber do not change due to temperature and humidity changes. It is an object of the present invention to provide a conductive brush excellent in printed image and print durability.

The object of the present invention described above is achieved by the following configuration.
(1) A polyamide fiber having a single-fiber fineness of 3.0 dtex or less composed of a polyamide having a dicarboxylic acid unit mainly composed of a sebacic acid unit and a conductive carbon, wherein the content of the conductive carbon is in the polyamide fiber The electroconductive polyamide fiber which is 15-35 mass% and single yarn fineness CV% is 8.0% or less.
(2) The conductive polyamide fiber according to (1), wherein the stress at 3% elongation is 0.7 to 1.1 cN / dtex.

  According to the present invention, there is provided a conductive polyamide fiber having a small single yarn fineness and a small variation without a change in resistance value or fiber length due to temperature and humidity changes, and a conductive brush excellent in printed image and print durability. can do.

  The polyamide used for the conductive polyamide fiber of the present invention is a polyamide having a dicarboxylic acid unit containing a sebacic acid unit as a main component. By using a polyamide having a dicarboxylic acid unit containing a sebacic acid unit as a main component, the hygroscopicity and heat shrinkage of the conductive polyamide fiber become low, and the change in resistance value and fiber length of the conductive polyamide fiber due to temperature and humidity changes. Is small. Therefore, when printing is started from stop, or even if there is an environmental change due to temperature and humidity, the distance between the tip of the conductive brush and the photosensitive member or roller is kept constant, and charging uniformity and environmental stability become high. A conductive brush excellent in printed image can be obtained. In addition, the amount of pressing the conductive brush against the photosensitive member and the roller is reduced, the wear of the conductive brush and the accumulation of toner are reduced, and a conductive brush excellent in printing durability can be obtained. Furthermore, sebacic acid is an excellent material for the global environment because it is refined from castor oil seeds.

  The dicarboxylic acid component constituting the polyamide used in the present invention is mainly composed of sebacic acid units as described above, and preferably 80 mol% or more of the dicarboxylic acid units are sebacic acid units, and is 90 mol% or more. More preferably, all are sebacic acid units. Examples of dicarboxylic acids constituting dicarboxylic acid units other than sebacic acid units include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, phthalic acid, isophthalic acid, terephthalic acid, etc. It can be mentioned.

  There is no particular limitation on the diamine unit constituting the polyamide, and as the diamine constituting the diamine unit, a diamine component having 2 or more carbon atoms, preferably 4 to 10 carbon atoms, more preferably 4 to 6 diamine components may be mentioned. Specifically, putrescine, 1,5-pentanediamine, hexamethylenediaminetrimethylenediamine, nonanediamine, methylpentanediamine, phenylenediamine, ethambutol and the like can be mentioned.

  Moreover, as long as the effects of the present invention are not impaired, it is also possible to copolymerize aminocarboxylic acids and lactams, and the content thereof is a unit composed of diamine and dicarboxylic acid and an aminocarboxylic acid (or lactam It is preferable that it is 10 mol% or less with respect to the sum total of unit).

  Preferred examples of the polyamide of the present invention include nylon 210, nylon 310, nylon 410, nylon 510, nylon 610, nylon 910 and the like, nylon 410, nylon 510, nylon 610 and nylon 910 are more preferable, and nylon 410, nylon 510 And nylon 610 are more preferable. Among these, nylon 510 and nylon 610 are preferable from the viewpoint of providing a conductive polyamide fiber having stable polymerizability and excellent dispersibility of carbon black.

  The polyamide of the present invention preferably has a relative viscosity of 2 to 4. The relative viscosity is measured at 25 ° C. using an Ostwald viscometer in a 98% concentrated sulfuric acid solution of 1% by mass of polyamide resin. By setting it as such a range, when dispersing conductive carbon such as carbon black in the polyamide or when it is melted and extruded, fiber strength can be maintained without breaking the carbon structure. Therefore, it is possible to suppress problems such as uneven charging and printing defects when using a conductive brush. More preferably, it is 2.5-3.5.

  The conductive polyamide fiber of the present invention has a content of conductive carbon in the fiber of 15 to 35% by mass. When the content of the conductive carbon is less than 15% by mass, the specific resistance value of the polyamide fiber is increased, the conductivity is lost, and the charge can not be provided, so that it does not function as a conductive brush. In addition, when the content of the conductive carbon exceeds 35% by mass, the spinnability decreases in the production of polyamide fibers, and the production becomes difficult. Preferably it is 20-30 mass%.

  Examples of the conductive carbon include carbon black and carbon nanotubes, and carbon black is preferably used.

  The carbon black used in the present invention is not particularly limited as long as it is a powder having conductivity such as furnace black, channel black and acetylene black, but the size of the powder particle is small and relatively uniform, since it is relatively uniform. Black is preferred. If the particles are large, it is preferable to use those having a particle diameter of 2 μm or less, in consideration of suppression of increase in filtration pressure during spinning, breakage of threads during spinning, and improvement of fiber strength. In addition, the particle diameter of carbon black measures primary particle diameter with a laser diffraction apparatus.

  The conductive polyamide fiber of the present invention has a single yarn fineness of 3.0 dtex or less. As described above, as the image quality is improved, the densification of the conductive brush is in progress, and by setting the density in this range, it is possible to realize the high density. A conductive brush excellent in printed image can be obtained. In addition, when the single yarn fineness exceeds 3.0 dtex, the conductive brush can be blurred or streaked in the printing state due to printing and stopping for a long time, so the printing durability is poor. Preferably it is 2.5 dtex or less.

  The conductive polyamide fiber of the present invention has a single yarn fineness CV% of 8.0% or less in order to equalize the fatigue of each single yarn when printing using a conductive brush for a long time. If the single yarn fineness CV% exceeds 8.0%, the load will differ in the thick and thin portions of the single yarn due to continuous use, and printing and stoppages may occur in the printing state for a long time, so the conductivity will be conductive. Does not function as a sexual brush. Preferably it is 6.0% or less.

The conductive polyamide fiber of the present invention preferably has a specific resistance of 10 ³ to 10 ⁸ Ωcm at a temperature of 20 ° C. and a humidity of 30% RH. By setting this range, it is possible to suppress problems such as uneven charging and printing defects when using a conductive brush.

  The conductive polyamide fiber of the present invention preferably has a stress at 3% elongation in a fiber tensile test of 0.7 to 1.1 cN / dtex. The stress at 3% elongation in the tensile test of fiber is subjected to a tensile test under the constant speed elongation condition shown in JIS L1013 (chemical fiber filament yarn test method, 2010), and the sample in the tensile strength-elongation curve is Calculated from the strength at 3% elongation point. This strength is divided by the fineness of the fiber to give a stress per unit fineness at 3% elongation. The stress per unit fineness at 3% elongation is a parameter indicating the rigidity of the fiber, and the larger the value, the more rigid the fiber. By setting it as this range, when it is set as a conductive brush, the rigidity of a fiber increases and printing durability improves. More preferably, it is 0.8 to 1.0 cN / dtex.

  The manufacturing method of the electroconductive polyamide fiber of this invention is demonstrated.

  As a method of incorporating conductive carbon in the conductive polyamide fiber of the present invention, there is a method of blending and melting conductive carbon to polyamide pellets, blending and melting master pellets containing high concentration of conductive carbon to polyamide pellets The method of adding the conductive carbon to the molten polyamide and kneading it, the method of kneading the polyamide containing the high concentration conductive carbon of the molten state to the molten polyamide, and the like can be mentioned.

  In the production of the conductive polyamide fiber of the present invention, it is important to uniformly disperse the conductive carbon in the polyamide having a dicarboxylic acid unit having a sebacic acid unit as a main component. A polyamide having a dicarboxylic acid unit containing a sebacic acid unit as the main component is inferior in fluidity of conductive carbon at melting as compared to nylon 6 exemplified in Patent Document 1, so that the conductive carbon is uniformly contained in the polyamide. It is difficult to disperse it in a single yarn, and the single yarn fineness variation tends to be remarkable. Therefore, as a means for improving the dispersibility of the conductive carbon, it is preferable to control under filtration conditions. For example, sand mesh up and application of metal staple fiber filter can be mentioned. The sand mesh is preferably 100 to 120, and the metal short fiber filter is preferably a sintered filter of metal short fibers having a cross section of a substantially polygonal shape. By taking such means, the single yarn fineness CV value can be controlled to 8.0% or less.

  In the production of the conductive polyamide fiber of the present invention, the production process may be a known melt spinning technique. Regarding the production method by melt spinning, a two-step method (a method in which an undrawn yarn is once wound and then stretched), a high speed spinning method which is one step (spinning speed is as high as 4000 m / min or more) Although it can be manufactured by any method such as the method of omitting PO, the production of POY), the high-speed spinning and drawing method (the method of continuously performing the spinning and drawing process), the unit at 3% elongation in the tensile test of fibers A two-step process is preferred to obtain fibers with a stress per denier of 0.7 to 1.1 cN / dtex.

  As an example of the two-step method, a polyamide resin containing conductive carbon is melted, filtered using the known spin pack under the above-mentioned preferable filtration conditions, discharged from the discharge hole of the spinneret, and cooled. Refuel and wind at a speed of 1000 m / min or less to obtain an undrawn yarn. Subsequently, the undrawn yarn is drawn or thermally drawn in a separate step, and then wound at a speed of 400 to 800 m / min to obtain a drawn yarn.

  In order to achieve uniform and stable fiber orientation, it is preferable to obtain an undrawn yarn at a spinning draft of 100 or less and an oiling position (a distance from immediately below the spinneret to the oiling point) of 2000 mm or more. Under such conditions, the stress per unit fineness at 3% elongation in a tensile test of fibers can be 0.7 to 1.1 cN / dtex.

It is preferable to obtain drawn yarn at a draw ratio of 2.5 to 3.5 times and a heat drawing temperature of 100 to 190 ° C. Under such conditions, the specific resistance value at a temperature of 20 ° C. and a humidity of 30% RH can be 10 ³ to 10 ⁸ Ωcm. The specific resistance value is a bundle of conductive polyamide fibers in the form of a bundle of 1000 dtex, and the measurement yarn length is 10 cm, and left for 18 hours or more at a humidity of 65% RH. The specific resistance value is calculated from the length and the yarn mass. The specific resistance value changes depending on the concentration of conductive carbon, and when the concentration of conductive carbon is high, the specific resistance value is low, and when the concentration of conductive carbon is low, the specific resistance value is high.

  The conductive polyamide fiber of the present invention may contain various additives as long as the effects of the present invention are not impaired. The additive is, for example, a stabilizer such as a manganese compound or a magnesium compound, a plasticizer, a lubricant such as a higher fatty acid compound, a flame retardant, a fibrous reinforcing agent, an antioxidant, a light resistant agent and the like.

  Among these, the higher fatty acid compound as a lubricant improves the melt polymer fluidity of the polyamide containing conductive carbon, so the share of the carbon structure is reduced when the conductive carbon is dispersed or when it is melted and extruded. As a result, the specific resistance value of the conductive polyamide is lowered. For this reason, since content of electroconductive carbon can be decreased, the intensity | strength of an electroconductive polyamide fiber becomes high, and it can suppress a fluff and a thread breakage in the process for producing a spinning yarn breakage | shortage or a brush. Moreover, in the case of the conductive brush up to now, when the number of printed sheets increases, toner accumulates in the brush and the resistance value of the brush surface becomes high, so there is a problem that the print density becomes thin. As a result, the friction on the fiber surface can be reduced, the accumulation of toner in the brush can be suppressed, and the number of printed sheets can be increased. The amount of the higher fatty acid compound added is preferably 0.5 to 5% by mass, more preferably 3% by mass or less, and still more preferably 2.8% by mass or less in the polyamide fiber. As an example of a higher fatty acid compound, it is preferable that it is C10-C30, Preferably it is 15-20, although saturated and unsaturated any may be sufficient, it is preferable that it is a saturated higher fatty acid compound. Examples of the form of the compound include metal salts (for example, alkali metal salts or alkaline earth metal salts, aluminum salts and the like, preferably alkaline earth metal salts), ammonium salts, esters and the like, among which metal salts are preferred. preferable. Preferred examples of the metal species of the metal salt include calcium, zinc, magnesium, barium and aluminum.

  Specific examples of higher fatty acid compounds include arachidonic acid compounds, isostearic acid compounds, undecylenic acid compounds, oleic acid compounds, stearic acid compounds, palmitic acid compounds, behenic acid compounds, myristic acid compounds, lauric acid compounds, lanolin fatty acid compounds, Hard lanolin fatty acid compounds, soft lanolin fatty acid compounds, linoleic acid compounds, linolenic acid compounds and the like can be mentioned. Among these, stearic acid compounds are inexpensive and easy when many solid substances are contained in the polyamide.

  Furthermore, among the stearic acid compounds, metal compounds are more preferable because the melt polymer fluidity of the polyamide is improved by the addition of a small amount. Examples of this metal stearate include calcium stearate, zinc stearate, magnesium stearate, barium stearate, aluminum stearate and the like. In addition to the stearic acid compound, it may be used in combination with other higher fatty acid compounds such as palmitic acid compound and myristic acid compound. Among these, zinc stearate is more preferable because the molten polymer flowability of the polyamide is improved by a smaller amount.

  The conductive polyamide fiber of the present invention is made into a conductive brush by electrostatic flocking on a metal shaft or winding a fabric which has been made into a woven fabric and wound around a metal. A conductive brush for dry copying machines of the electrophotographic recording system is an application brush that contacts the photosensitive member in place of non-contact corona discharge, a cleaning brush that removes the charge and toner remaining on the photosensitive member, and a photosensitive member A toner supply brush that charges the toner in the toner cartridge to promote adsorption of the toner, and a transfer brush that applies the reverse charge to the printing paper to transfer the toner supplied to the photosensitive member to the printing paper.

  When using a conductive brush by electrostatic flocking, make the conductive polyamide fiber into a form of tow (converging of continuous filaments) and heat treat with hot water at 80 to 98 ° C for 30 to 60 minutes to cut a guillotine cutter etc. It will be short fiber by machine. The hot water treatment during the manufacturing process not only shrinks the conductive polyamide and reduces the variation in the electrical resistance value, but also has the effect of reducing the change in the resistance value over time after forming the conductive floc and the conductive brush. .

  Also, although the cut surface of the staple fiber is determined by the structure of the cutting machine and the relationship between the cutter and the fiber, the conductive carbon-containing polyamide fiber and the cutter contact at a right angle and cut at a right angle to the fiber axis Is preferred. At this time, if it is cut in a normal tow state, the pressure of the cutter will crush the tow, and the position of the fiber will move and the length variation of the cut fiber is likely to occur. It is preferable to make it difficult for the fibers to move at the time of cutting, for example, a method of winding and cutting while being wound, or filling a tow into a resin-made container and cutting it together with the container. In addition, it is good to remove the cut | disconnected paper, a film, the container made from resin, etc. with a sieve. Furthermore, although the fibers to be tow are bundled, if the amount of bundling is reduced, the movement of the fibers at the time of cutting will be reduced, and the fiber length variation will be reduced, but since the work increases, the fineness to be bundled to tow is 50 to 5,000,000. It is preferable to bundle them so as to be dtex. In addition, it is preferable that there is no twist or bending in the short fiber as an electroconductive floc from the point of the rise property of a floc.

  The conductive floc is applied with an adhesive to the substrate and flocked using static electricity. Electrostatic flocking is electrically affected when a minute object intervenes in the electric field by high voltage. The electrical effect is that the minute object is charged and attracted from one pole to the other. That is, when applying DC high voltage to metal, an electric field (E) is generated between them. The magnitude of this electric field has a relationship of E = V / d when the voltage (V) and its distance (d), and the charge (q) of the small object present in this electric field is the attraction force (F) Pulled under the force given by) = Eq. Flock refers to this small object. In electrostatic flocking, the positive electrode is referred to as a high voltage electrode, the negative electrode is referred to as a ground electrode (earth electrode), and the magnitude of the electric field is given a predetermined voltage V by a high voltage generator. In electrostatic flocking, the base material is placed parallel to the interpolar surface and the polar surface, and flock sticks to the base material coated with the adhesive at right angles to the base material during the interpolar lifting. Therefore, the flying property is determined by the charge (q) of the flock.

  The conductive floc is obtained by cutting the conductive polyamide fiber into a short fiber and applying an electrodeposition treatment agent. The application amount of the electrodeposition treatment agent is preferably 1 to 7% by mass, based on the amount of ash of the conductive floc. The ash content is calculated by the ash method (JIS L 1015 (1999)) of the chemical fiber staple test method defined by JIS. The electrodeposition treating agent is a treating agent for giving an electric charge in order to perform electrostatic flocking, and specifically, a treatment in which a short fiber electrically acts to give a good lifting effect in an electric field. It is an agent. If the deposition of the electrodeposition treatment agent is too small, the surface resistance value of the conductive floc becomes low and the flying property becomes worse due to the inherent resistance value of the polyamide fiber containing the conductive carbon. If the deposition of the electrodeposition treatment agent is excessive, crystals will precipitate in the drying step during electrodeposition, and will adhere to the wall of the flocking chamber during electrostatic flocking, causing metal corrosion and promoting gelation of the adhesive. As a result, the problem of extremely reducing the adhesive strength of the conductive floc occurs. Preferably, it is 3 to 5% by mass.

  As an electrodeposition processing agent constituting the conductive floc, for example, inorganic acids such as tannic acid, sodium chloride, barium chloride, magnesium chloride, magnesium chloride, magnesium sulfate, sodium nitrate, zirconium carbonate and the like, an anionic surfactant, a nonionic surfactant and the like Surfactants, organosilicon such as colloidal silica, alumina sol, etc. may be mentioned. When using a conductive brush with inorganic salts or a surfactant having an antistatic effect as an electrodeposition treatment agent, the surface treatment agent of the photoreceptor or toner is formed of an organic component in a dry copying machine or printer, etc. Depending on the components, the surface may be altered to deteriorate the quality of printing. For this reason, organic silicon and alumina sol are preferable from the viewpoint that they should not react with the surface treatment agent of the photosensitive member and toner, and from the viewpoint of electrical conductivity, dielectric constant and separation.

  The electrodeposition treatment of the conductive floc is not particularly limited. For example, the conductive polyamide short fibers cut into short fibers are dipped in an aqueous solution of an electrodeposition treatment agent diluted with a binder such as water to conduct electrodeposition treatment. Moreover, it is preferable to use 30-100 g / L of the aqueous solution of an electrodeposition process agent from the viscosity of aqueous solution and the efficiency of electrodeposition process.

  The electrodeposition treating agent preferably contains organic silicon, and more preferably colloidal silica. Colloidal silica is particularly excellent in dispersibility in water, so that uniform electrodeposition on short fibers is easy. In addition, colloidal silica is less likely to come off due to friction because it specifically bonds with the hydroxyl group of polyamide.

The electrodeposition treatment agent may be an aqueous solution of only organic silicon, but it is more preferable to apply a mixed aqueous solution of colloidal silica and alumina sol. Colloidal silica and alumina sol have good mixability, and when applied with a high voltage, it is easy to obtain a high charge, and it is possible to obtain a conductive floc having excellent floc separability. In addition, when using polyamide fiber containing conductive carbon whose specific resistance value is less than 10 ⁶ Ω cm, even if high voltage is applied, electric charge can not be obtained and the flightability is reduced, but mixing of colloidal silica and alumina sol By applying the aqueous solution, the resistance value of the flock surface becomes 10 ⁶ to 10 ⁸ Ωcm, and the ascent property is improved. In the method of mixing the colloidal silica and the alumina sol, it is preferable to mix the colloidal silica and the alumina sol in an aqueous solution state, since the increase in viscosity is suppressed and uniform dispersion is obtained. The ratio of mixing is preferably 6 to 1 to 3 to 1 for colloidal silica and alumina sol, since uniform dispersion can be obtained and the resistance value of the flock surface can be made the target resistance value.

  The electrodeposited floc is dewatered using a rotary dehydrator and dried at 100 to 130 ° C. for 30 to 60 minutes, followed by sieving to align the fiber length to a certain length.

  The fiber length of the conductive floc using the conductive polyamide fiber of the present invention is preferably 0.1 to 5 mm. By setting it in this range, a conductive brush flocked vertically to the substrate can be formed without entanglement of flock products with each other, so that the flock is unlikely to come off and the distance between the adhesive having low conductivity and the photosensitive member or roller Since the generation of sparks can be suppressed, damage to the photosensitive member and roller can be prevented. The diameter of the conductive floc is preferably 60 μm or less from the relationship between the conductive floc and the force to be anchored to the adhesive layer applied to the substrate and the flocking density when electrostatic flocking is performed.

  The conductive brush using the conductive polyamide of the present invention is a conductive brush prepared by electrostatic flocking the conductive floc, and is used for static electricity removal, application of charge, removal of dust and the like.

  The conductive brush consisting of electrostatic flocking applies an adhesive to the core material which is a cylindrical metal rod, applies a voltage of 10K to 50KV, flocks the conductive floc by electrostatic flocking, dries it, removes it, and shirrs if necessary. To make a brush. The core material which is a metal rod is not particularly limited as long as it has conductivity, but preferably stainless steel is used. Although the adhesive is not particularly limited, for example, an acrylic resin, polyvinyl acetate, polyurethane, a synthetic rubber, a natural rubber or the like is a main component, and preferably an acrylic is used. Further, it is preferable to use an adhesive having conductivity, in which the adhesive contains a conductive material such as conductive carbon.

  A conductive brush made of a fabric is woven as a pile and then backed with a conductive backing agent, and then a pile tape cut to a width of 10 to 30 mm is wound around a cylindrical metal rod around a bias or simply pile woven fabric on a plate It is obtained by pasting and making it like a brush.

  In the case where a conductive brush is used as a woven fabric and a brushed fabric is wound around a metal or the like, conductive polyamide fibers are woven as a raised blanket by pile weave. Here, the conductive polyamide fiber is W-woven to stand up on the base fabric as a pile yarn. The base cloth is a base for raising the conductive polyamide fiber as a pile yarn, and the fiber used for the fabric may be conductive or insulating, but from the viewpoint of cost, insulating fiber is preferable Used. A polyester spun yarn is preferably used as a fiber used for the fabric. The upholstery obtained by the above is dried and heat-treated by passing it through a heating furnace at about 120 to 200 ° C. in order to prevent shrinkage of the base fabric over time.

  The dry and heat-treated raised blanket stabilizes the brush resistance value as the conductive brush, and is subjected to a coating treatment as a post-treatment from the viewpoint of preventing the conductive polyamide fiber from falling off and falling off.

  The coating process is performed by applying a conductive coating agent to the opposite side of the upset of the conductive polyamide fiber of the upholstery, and drying after application at a temperature of about 50 to 100 ° C. In addition, it is preferable that the volume specific resistance value of the raised blanket after a coating process is 10-500 ohm-cm.

  The conductive coating agent comprises a binder (polymer), an aqueous dispersion (emulsion liquid) containing a solvent in which the binder can be dissolved, or a binder, and a conductive substance, which are uniformly mixed in advance.

  The polymer to be used as the binder is not particularly limited. For example, a copolymer of an aromatic vinyl monomer and a conjugated diene monomer, a copolymer of a nitrile group-containing vinyl polymer and a conjugated diene monomer Acrylic acid ester copolymers, ethylene oxide-propylene oxide copolymers, etc. can be used. Among them, it is preferable to use a copolymer of an aromatic vinyl monomer and a conjugated diene monomer, and as a specific example thereof, a copolymer of styrene and butadiene can be mentioned. There is no limitation in particular in the monomer composition ratio and molecular weight of a copolymer, These can be manufactured by a well-known method.

  As the conductive material, carbon black, graphite carbon, carbon fiber, metal powder, metal whisker, or the like can be used. Among these, carbon black is preferably used in terms of availability, handling and the like.

  Next, the conductive brush raised blanket obtained by the above method is cut with scissors or the like to obtain, for example, a ribbon-shaped raised blanket having a width of 20 mm and a length of 400 mm. Then, partially paste the double-sided tape on a conductive shaft, for example a stainless steel shaft with an outer diameter of 8 mm and a length of 250 mm (if insulating double-sided tape is attached to the entire surface, between the raised blanket and the shaft Electricity will not flow). The double-sided tape may be insulating or conductive. A ribbon-like raised blanket is spirally wound on the stainless steel shaft with respect to the longitudinal direction of the shaft, and fixed to the surface of the shaft with double-sided tape.

  Next, the tip of the brush is brought into contact with the hot plate at about 120 to 200 ° C. while rotating around the shaft, and the tip is set in the same direction as the conductive brush. At this time, it may be set while hitting the steam.

  Hereinafter, the present invention will be described in detail by way of examples. In addition, the measuring method in the Example used the following method.

A. Relative Viscosity 0.25 g of a sample was dissolved in 100 mL of sulfuric acid having a concentration of 98 wt% to 1 g, and the flow time (T1) at 25 ° C. was measured using an Ostwald viscometer. Subsequently, the flow time (T2) of only 98 wt% sulfuric acid was measured. The ratio of T1 to T2, that is, T1 / T2 was taken as the relative viscosity of sulfuric acid.

B. Fineness A sample is wound 200 times with a measuring machine with a frame width of 1.125 m, dried with a hot air drier (105 ± 2 ° C x 60 minutes), weighed with a balance, and official moisture percentage The fineness was calculated from the multiplied value. The measurement was performed four times, and the average value was defined as the fineness. In addition, a value obtained by dividing the obtained fineness by the number of filaments was defined as a single fineness of yarn.

C. Strength Measured under constant-speed elongation conditions shown in JIS L1013 (chemical fiber filament yarn test method, 2010), using “TENSILON” (registered trademark) UCT-100 manufactured by Orientec Co., Ltd. as a measuring instrument. The strength was determined by dividing the maximum strength by the fineness. The measurement was performed 10 times, and the average value was taken as the intensity.

D. Stress at 3% elongation A tensile test of the sample is carried out according to the method described in section C, and the strength at the point where the sample in the tensile strength-elongation curve shows 3% elongation is determined. did. The measurement was performed ten times, and the average value was taken as the stress at 3% elongation.

E. Dimensional stability The sample left for 24 hours in an environment of 20 ° C. × 65% RH is wound 20 times with a 1.125 m measuring machine, and a load of 1/30 g / dtex is applied to measure the test length. Next, the sample is left for 24 hours in an environment of 30 ° C. × 90% RH, a load of 1/30 g / dtex is applied, and a test length is measured, and calculated from the following equation.
Sa = (LH-LL) / LL × 100
Sa: Dimensional stability (%)
LH: Trial length at 30 ° C. × 90% RH LL: Trial length at 20 ° C. × 65% RH.

F. Printed image After leaving the copier for 24 hours under the environment of 20 ° C × 65% RH and 30 ° C × 90% RH, copy the test chart issued by the Electrophotographic Society under the same environment, print 1000 sheets each, 1000 The printing conditions (fading, streaks) of the sheets were compared with one another, and 10 persons rated them according to the following criteria below.
10 points: no difference (no blur or streaks)
5 points: Some difference is seen (not noticeable, but faint, streaks)
1 point: a difference is seen (fading, streaks are clearly observed)
It was classified according to the following standard by the point which added this for 10 persons.
:: 75 or more ○: 50 or more and less than 75 points Δ: 25 or more and less than 50 points ×: less than 25 points

G. Printing Durability After leaving the copier for 24 hours under an environment of 20 ° C. × 65% RH, 10000 sheets of test charts issued by the Electrophotographic Society are printed, and the first and 10000th sheets are printed (fading, streaks) The following criteria were evaluated by 10 persons based on the following criteria.
10 points: no difference (no blur or streaks)
5 points: Some difference is seen (not noticeable, but faint, streaks)
1 point: a difference is seen (fading, streaks are clearly observed)
It was classified according to the following standard by the point which added this for 10 persons.
:: 75 or more ○: 50 or more and less than 75 points Δ: 25 or more and less than 50 points ×: less than 25 points

H. Electrically conductive brush resistance value A brush was placed on a stainless steel metal plate, a weight of 25 g was placed on both sides on the core of the brush, and the resistance when 10 V was applied was measured using a resistance meter (SM-8213 manufactured by TOAKDD). . The measurement was performed under the same environment after leaving the brush in an environment of 20 ° C. × 65% RH for 24 hours.

I. Single yarn fineness CV%
Using a motorcycle Blo type Denier Computer (Search Co., Ltd. DC-11B), under an environment of 20 ° C. × 65% RH, apply an initial load of 0.1 g per 1.11 dtex to a test length of 5 mm of polyamide fiber to obtain a fiber sample The fineness (D) was measured from the vibration of This was measured 3 times each for all single yarns in polyamide fiber, and CV% was calculated.
D = 2.205 × 10 ⁸ × (W / L ² F ² )
D: denier value (d)
W: Weight (g)
L: sample length (cm)
F: Frequency of yarn (Hz).

Example 1
100% sebacic acid and 100% hexamethylenediamine in nylon 610 (relative viscosity 2.7) having a dicarboxylic acid component constituting polyamide and a diamine component are kneaded with furnace black as carbon black having an average particle diameter of 0.035 μm Conductive nylon 610 pellets were produced. Then, the polymer is melted at a melting temperature of 280 ° C., and the polymer is filtered using a metal short fiber sintered filter having a sand roughness of 100 mesh and a cross section of a substantially polygonal shape, and then discharged from a circular hole die having a hole diameter of 0.25 mm. After cooling, the spinning oil is diluted with water and refueled so that the yarn adhesion amount is 0.7%, the take-up speed is 800 m / min, the spinning draft 90, the refueling position (distance from immediately below the mouthpiece to the refueling point) The undrawn yarn was wound at 4000 mm. Then, after aging the undrawn yarn for 48 hours under the environment of temperature 25 ° C. and absolute humidity 16.6 g / m ³ , the feeding roller speed 200 m / min of the stretching machine, hot plate temperature 170 ° C., stretching roller speed 500 m / min Then, the fiber was subjected to a twist of 15 T / m using a down twister to obtain a 110 dtex 48 filament conductive polyamide fiber. The content of carbon black is 25% by mass.

  The obtained conductive polyamide fiber is taken 10,000 times using a 3 m casses pick-up machine once to make a tow shape of about 1,100,000 dtex, and then heat treated with hot water at 98 ° C. for 30 minutes Then, the tow was wound with a kraft paper having a tensile strength of 0.5 N, and cut into a fiber length of 1.5 mm short fiber shape with a guillotine cutter to obtain a conductive polyamide short fiber. 50 g / L aqueous solution of colloidal silica (Snowtex-O manufactured by Nissan Chemical Industries, Ltd.) and alumina sol (Alumina sol -100 manufactured by Nissan Chemical Industries, Ltd.) 50 g / L to the obtained conductive polyamide short fibers as an electrodeposition processing agent The aqueous solution was immersed for 30 minutes in an aqueous solution of 40 ° C. mixed at a mixing ratio of 6: 1 for electrodeposition processing. Next, after drying at 120 ° C. for 45 minutes, sieving was carried out with a 40 mesh wire mesh to obtain fibers having a diameter of 30 μm.

  Next, an adhesive of acrylic resin containing conductive carbon is applied to a core material which is a cylindrical stainless steel metal rod, a voltage of 20,000 V is applied, electrostatic flocking is performed by the down method, drying at 180 ° C., removal I got the process of hair, shirring and made the brush. The results are shown in Table 1.

Example 2
Dilute the furnace black as a carbon black with an average particle size of 0.035 μm in nylon 510 (relative viscosity 2.7) in which the dicarboxylic acid component constituting the polyamide is 100% sebacic acid and the diamine component is 100% 1,5-pentanediamine A conductive polyamide fiber, a conductive flock, and a conductive brush were produced in the same manner as in Example 1 except that they were embedded. The results are shown in Table 1.

Example 3
A conductive polyamide fiber, a conductive flock, and a conductive brush were produced in the same manner as in Example 1 except that channel black was kneaded into nylon 610 as carbon black having an average particle diameter of 0.050 μm. The results are shown in Table 1.

Example 4
A conductive polyamide fiber, a conductive flock, and a conductive brush were produced in the same manner as in Example 1 except that the single yarn fineness was 3.0 dtex (144 dtex 48 filaments). The results are shown in Table 1.

Example 5
A conductive polyamide fiber, a conductive floc and a conductive brush were produced in the same manner as in Example 1 except that the content of furnace black as carbon black was 15% by mass. The results are shown in Table 1.

Example 6
A conductive polyamide fiber, a conductive floc and a conductive brush were produced in the same manner as in Example 1 except that the content of furnace black as carbon black was 35% by mass. The results are shown in Table 1.

Comparative Example 1
A conductive polyamide fiber is used in the same manner as in Example 1 except that nylon 6 (relative viscosity 2.6) having 100% ε-caprolactam as a component constituting the polyamide is used, and the filtering conditions are changed to a sand roughness 80 mesh and a wire mesh filter. , Conductive floc, conductive brush was produced. The results are shown in Table 2.

Comparative example 2
Thermal black is kneaded into nylon 610 as carbon black having an average particle diameter of 0.085 μm, and the filtering conditions are the same as in Example 1 except that the sand coarseness is 80 mesh and the fineness of single yarn CV is 10.7% as a wire mesh filter. The conductive polyamide fiber, the conductive floc, and the conductive brush were produced. The results are shown in Table 2.

Comparative example 3
Conductive polyamide fiber, conductive flock, conductive property as in Example 1 except that single yarn fineness is set to 8.5 dtex (170 dtex 20 filaments), and filtration conditions are changed to sand roughness 80 mesh and wire mesh filter. A brush was made. The results are shown in Table 1.

Comparative example 4
Conductivity was carried out in the same manner as in Example 1 except that the content of furnace black was 45 mass% as carbon black having an average particle diameter of 0.035 μm in nylon 610 and the filtration conditions were changed to sand roughness 80 mesh and a wire mesh filter. Polyamide fibers, conductive flocks and conductive brushes were made. The results are shown in Table 1.

  From the results of Table 1 (Examples 1 to 6), it can be seen that the conductive polyamide fiber of the present invention can provide a conductive brush excellent in printing durability and printed image.

  On the other hand, since the conductive polyamide fiber using polyamide 6 as nylon 6 (Comparative Example 1) is inferior in dimensional stability and rigidity, it is understood that the printed image is difficult and the printing durability has a problem.

  It can be seen that the conductive polyamide fiber (Comparative Example 2) has a variation in single yarn fineness, so that there is a problem in the printed image and a problem in the printing durability.

  It can be understood that since the conductive polyamide fiber of the single yarn diameter degree (Comparative Example 3) can not densify the brush, the printing durability is difficult and the printed image has a problem.

  The conductive fiber containing 45% of furnace black as carbon black (Comparative Example 4) has variation in single yarn fineness, so that it is understood that the printed image has a problem and the printing durability has a problem.

Claims (2)

  A polyamide fiber having a dicarboxylic acid unit mainly composed of a sebacic acid unit and a polyamide fiber having a fineness of 3.0 dtex or less composed of a conductive carbon and the content of the conductive carbon in the polyamide fiber is 15 to 35 The electroconductive polyamide fiber which is mass% and single yarn fineness CV% is 8.0% or less.   The conductive polyamide fiber according to claim 1, wherein a stress at 3% elongation is 0.7 to 1.1 cN / dtex.