JP4418279B2 - Static elimination brush - Google Patents

Description

  The present invention relates to a self-discharge type static elimination brush that can be used for copying machines, facsimiles, and other devices that require static elimination to remove static electricity from paper. The present invention relates to a static eliminating brush that has been improved to improve strength and repeated fatigue characteristics and enables long-term use.

  For example, in an electrostatic device that needs to remove static electricity generated on paper such as a paper, sheet, film, such as a copying machine, a facsimile, a printing machine, or a film manufacturing apparatus, when static electricity remains on the paper, image unevenness Will cause trouble. Therefore, a static eliminating brush is used as a means for removing static electricity from paper and discharging it.

  As shown in FIG. 1, this static elimination brush has a conductive thin wire a serving as a discharge electrode attached to a metal support c. Usually, the converging wires b obtained by converging a plurality of fine wires a are equally spaced. A method of widely fixing the focusing line b on the fixing tape d and affixing it to the metal support c is widely adopted.

  When using such a static elimination brush, the static elimination brush is discharged from the metal support c through the fine wire a through the ground wire of the equipment body to the outside of the equipment through the thin wire a in contact with the static-charged paper to be fed. To do. Here, in order to carry out static elimination more reliably, the papers need to be brought into sufficient contact with the fine wire a. Therefore, the papers are fed in a state where the fine wire a is largely pushed and bent. Each time a product is fed, it will be repeatedly bent.

And a discharging brush, Patent Document 1 proposes to use, for example, a plurality of the twisted strands of fine wire having a 200 Kg / mm ² or more strength as a focused beam, as a thin line, such as stainless steel, piano A high-strength crystalline fiber, a high-strength amorphous metal fiber, and the like are described together with the wire, and Patent Document 2 describes a converged inorganic fiber such as a carbon fiber, a conductive plating yarn, and a dyed yarn as a thin wire. ing.

Japanese Patent Laid-Open No. 6-151087 Japanese Patent Laid-Open No. 3-121009

However, although there is a description of stainless steel as one steel type of a thin wire with a tensile strength of 200 kg / mm ² or more described in Patent Document 1, what kind of steel type is selected in the stainless steel of other steel types is clearly indicated. For example, the use of general-purpose austenitic stainless steel such as SUS304 and SUS316 as shown in JIS-G4314 “Stainless Steel Wire for Spring” can be inferred. However, the strength of stainless steel changes due to work hardening such as wire drawing, and when accompanied by a large processing rate, processing strain remains inside the material, resulting in reduced toughness and fatigue characteristics. In steel, crystal grains in a heat treatment state before wire drawing are relatively large and low in strength. For this reason, even if work hardening is performed thereafter, a large strength cannot be obtained.

In conventional stainless steel, in order to achieve a high strength of 200 kg / mm ² However, since the fatigue of this thin wire is caused by this, the fiber material undergoes repeated bending for each paper feed, so that the tip of the converging wire is bent and deformed so as to spread outwardly. Plastic deformation and fan-shaped expansion, or fracture when it cannot withstand bending fatigue, will reduce static elimination performance, and the broken piece enters the working part inside the equipment and wears down the rotating part, Or it causes problems such as electrical troubles such as short circuit.

  As described above, the present invention is based on the premise that stainless steel is used as the thin wire for the static elimination brush electrode, and has a sufficient strength and fatigue resistance that can withstand repeated bending. Offering is an issue.

In the invention according to claim 1, a converging body focusing a plurality of fine metal wires having a specific resistance at room temperature of 100 μΩ · cm or less is fixed to a conductive support, and the fine metal wire has a wire diameter ( d) is 0.1 mm or less and the composition in mass% is C: 0.06 to 0.12%, Si: 0.3 to 0.9%, Mn: 0.3 to 1.0%, Ni: 8 0.0 to 9.0%, Cr: 18.11 to 19.0%, Mo: 0.54 to 1.0%, N: 0.1 to 0.25% , the balance being substantially inevitable impurities and Fe It is a static elimination brush which consists of an austenitic stainless steel hard wire with Mo and N added.

  The invention according to claim 2 is characterized in that the thin metal wire has a Young's modulus of 125,000 to 150,000 MPa and a wire diameter of 1 to 50 μm, and the invention of claim 3 provides the converging body. However, the invention according to claim 4 is characterized in that the converging body is subjected to low-temperature heat treatment at a temperature of 500 to 700 ° C. after the twisting process, It has a straightness of 1000 mm or less.

The static elimination brush is composed of austenitic stainless steel hard fine wire with an improved composition by adding Mo and N as its electrode material, so it has excellent strength and fatigue resistance, and it has fracture and deformation. This makes it possible to prevent static elimination brushes with a long life. In particular, by adding Mo and N, the crystal grains of the base stainless steel before wire drawing are refined to increase the strength, and as a result, a predetermined strength can be obtained at a relatively low processing rate during wire drawing. Therefore, it is possible to provide a stable structure, and to provide an electrode with improved fatigue characteristics .

  That is, the desired high strength characteristics can be obtained with a relatively small processing rate by the wire drawing process, which not only improves the wire drawing workability and improves the yield, but also causes processing distortion inside the material. Since it can be reduced, it becomes stable in terms of organization, and as a result, exhibits excellent resistance to repeated external forces such as bending, and enables a long life.

  Furthermore, an extra fine wire of 0.1 mm or less is used. This is because the object to be neutralized, for example, papers, sheets, films, etc. made of various materials, are not damaged by scratching and have sufficient elasticity to contact the papers. Therefore, a hard fine wire of 0.1 mm or less (preferably, for example, 10 to 50 μm) is used in the steel type.

  Further, when the metal thin wire has a Young's modulus of 125,000 to 150,000 MPa and a wire diameter of 1 to 50 μm, the effect is increased, and as the converging body according to claim 3, By using a twisted strand of a plurality of strands, the strength of the converging body can be increased, and the converging body is subjected to a low temperature heat treatment at a temperature of 500 to 700 ° C. after the twisting process, By having a straightness of 30/1000 mm or less, it becomes an excellent neutralizing body of a static elimination brush.

An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the neutralizing brush 1 of the present invention has a converging body 3 that converges a plurality of fine metal wires 2 fixed to a metallic support 4. The fine metal wire 2 has a wire diameter (d) of 0.1 mm or less and a composition in mass % of C: 0.06 to 0.12%, Si: 0.3 to 0.9%, Mn: 0.3 to 1.0%, Ni: 8.0 to 9.0%, Cr: 18.11 to 19.0%, Mo: 0.54 to 1.0%, N: 0.1 to 0. An austenitic stainless steel hard wire of 25%, the balance being substantially inevitable impurities and Fe, with addition of Mo and N is used.

In the metal composition, carbon (C) needs to be added in an amount of at least 0.03% in order to increase the predetermined mechanical strength, particularly the tensile and bending strength, as a fine metal wire, while 0.15% When a large amount is added so as to exceed the range, not only the work hardening is increased and the wire drawing workability is deteriorated, but also a carbide is formed to cause disconnection. In the present invention, the content is 0.06 to 0.12%. The silicon (Si) is the tensile strength has the advantage of increasing the hardness, which tends to lower the toughness exceeds 1.0% Runode, and 0.3 to 0.9 percent, more manganese (Mn ) is effective as an austenite forming element, also has the advantage of improving the wire drawability, the other hand, in order there is a problem such as lowering the mechanical strength 0. 3 to 1.0%.

Nickel (Ni) is indispensable as an element that stabilizes the austenite structure in stainless steel and densifies the passive film on the surface to improve the corrosion resistance, and enhances the mechanical properties of the material such as toughness, and is at least 8.0. However, if it exceeds 10.0%, the wire drawing workability is lowered, so the content is made 8.0 to 9.0% . Chromium (Cr) is the most abundant basic element in stainless steel, and has an effective function in the formation of austenite structures and the formation of passive films. For that purpose, addition of at least 18.11 % is necessary. On the other hand, if it exceeds 19.0%, the hardness, tensile strength, wire drawing workability and the like are lowered.

Molybdenum (Mo) has the advantage of improving the corrosion resistance and toughness of stainless steel, but on the other hand, Mo is also a ferrite-forming element, so austenite tends to become unstable, and the Ni content must be increased to compensate for this. Is required. Therefore, Mo: 0.54 to 1.0% is set.

Further, nitrogen (N) is an intrusion strengthening element that dissolves in the face-centered cubic lattice of iron like carbon, and has the advantage of increasing the strength, particularly the yield point, by refining the crystal, so that at least 0.1. On the other hand, if it exceeds 0.25%, the wire drawing workability will be affected. More preferably, it is 0.1 to 0.20%.

  This composition is made by actively adding Mo and N to refine the crystal grains of the base material stainless steel before wire drawing to increase the strength, and relatively little processing in wire drawing. Great strength is obtained at a high rate. Accordingly, it is possible to obtain an austenitic stainless steel hard wire that is stable in structure and can be an electrode material with improved fatigue characteristics.

  The metal thin wire 2 of the present invention preferably further refines the crystal grains and further increases the strength by adding any third element such as Ti, Nb, Al, etc. Each is about 0.05% or less. Examples of the inevitable impurities include P ≦ 0.045% and S ≦ 0.03%.

  The wire diameter of the fine metal wire 2 is 0.1 mm or less. This is because the object to be neutralized, for example, papers, sheets, films, etc. made of various materials, are not damaged by scratching and have sufficient elasticity to contact the papers. Therefore, the steel type is a hard thin wire of 0.1 mm or less (preferably, for example, 10 to 50 μm). By adding N and Mo, the proof stress and Young's modulus can be increased to make the Young's modulus 125,000 to 150,000 MPa, which is suitable for use as an electrode material for a static elimination brush.

On the other hand, the specific resistance at room temperature is 100 μΩ · cm or less, for example, 60 to 100 μΩ · cm, preferably 70 to 80 μΩ · cm, to reduce the resistance of the thin metal wire 2 and maintain the discharge performance. Here, the specific resistance means the electric resistance per unit cross-sectional area and unit length, and the smaller the specific resistance, the better the static elimination performance. For example, it is 140 μΩcm for amorphous metal, 120 μΩ · cm for Inconel, and 90 μΩ · cm or less (for example, 50 to 80 μΩ · cm) for the above-described Mo and N-added austenitic stainless steel hard wire according to the present invention. The specific resistance can be measured based on JISC2525. In addition, since the amorphous metal of the said characteristic is also used as a static elimination brush, it is clear that the austenitic stainless steel wire of this invention which has a specific resistance lower than this can be used as a static elimination brush.

  The stainless steel wire of such a material is improved in fatigue characteristics by performing cold wire drawing at a processing rate of about 60% to 93% and concentrating multiple pieces and performing low temperature heat treatment. An austenitic stainless steel hard wire as an electrode material that can be used as a static elimination brush can be obtained. In addition, since Mo and N are added as described above, the processing rate in wire drawing can be reduced, and the structural stability can be improved. Therefore, the straightness can be improved in the subsequent low-temperature heat treatment. It becomes easy.

Incidentally, in this embodiment, the subjecting the low-temperature heat treatment to the pre-focusing body 3A which focuses the plurality of thin metal wires 2, to form a bundle of 3 for discharging brush 1. As the pre-focusing body 3A, for example, a thin metal wire 2 that is obtained by collecting and collecting the root portion, or a focusing body that is glued with, for example, PVA and conductively treated, for example, may be used. It can also be set as the twisted wire which twisted about ~ 100 metal fine wires 2, especially the twisted wire which added the further twist. By making such a composite twisted wire, even if it is cut to a length of about 10 to 20 mm, the fine wires are prevented from being entangled with each other, so that the fine metal wires 2 are prevented from coming off from the focusing body 3, and each fine metal wire is The conductivity between the two can be imparted.

  The low-temperature heat treatment is performed for the purpose of releasing residual strain and improving straightness while maintaining the focused state of the preliminary focusing body 3A, and is performed at a relatively low temperature of about 300 to 700 ° C., for example. In this case, it is possible to preferably employ a tension annealing method in which the inside of the continuous furnace heated to the set temperature is passed in a free state, or heating is performed while applying a predetermined tension in order to improve straightness and strength. At this time, as the additional tension, for example, heating is performed while applying a tension within a range of 30 to 70% of the tensile strength of the focusing body 3. Also, this tension annealing method allows straightness to be 30/1000 mm or less even when the processing temperature is low, and the yield strength ratio ({0.2% yield strength / tensile strength} × 100) is, for example, 85 to 93%. It can be a hard fine wire with improved quality. The straightness 30/1000 mm means that the maximum separation distance (mm) from the axis (vertical line) drawn in the vertical direction at the lower end when a continuous stranded wire having a length of 1000 mm is suspended in a natural state is 30. That means.

The “hard wire” referred to in the present invention means a material having a tensile strength of 2000 N / mm ² or more and a large elastic property of a yield strength ratio of 85 to 93% as described above, and employs the tension annealing method. In addition, when the above-mentioned other conditions other than the heat treatment method are conceived, this numerical value including the straightness can be achieved by adjusting the conditions such as the heating temperature, time, and additional tension, thereby focusing the neutralizing brush 1 Line 3 can be obtained.

  The thus obtained focusing body 3 is excellent in strength and elasticity, can prevent bending deformation even if there is some carelessness, has excellent fatigue resistance, and can provide a long-life static elimination brush. . In addition, as shown in FIG. 1, the converging body 3 is made of, for example, an adhesive tape 5 made of metal or the like and made of a conductive support 4 made of metal or the like with a constant pitch P and the same height. And have electrical conductivity. At this time, the focusing body 3 may be attached in advance to the adhesive tape 5 side. The support 4 only needs to have at least a conductive path for discharging static elimination electrons to the outside, and forms a good conductive path of metal, carbon, or the like that is continuous at least in the length direction, and is electrically connected to the focusing body 3. Further, the support 4 may be formed by bending a metal plate or the like into a U-shape and placing the focusing body 3 between them and sandwiching and integrating them. The focusing body 3 is cut to a length of about 5 to 30 mm, for example. The bundles are arranged at predetermined intervals.

(1) Material and wire drawing The raw material of the composition of Examples 1-4 shown in Table 1 was prepared. The raw wire diameter was 0.15 mm, and soft heat treatment was performed at a final temperature of 960 ° C., and this was subjected to cold wet drawing at a processing rate of 98% to obtain a 19 μm ultrafine wire. On the other hand, as a comparative example, using SUS304 (Comparative Example 1) and SUS316 (SUS306),及Beauty Co-Fe-Cr-Si- B system amorphous metal wire (amorphous) (Comparative Example 3), as well Processing was carried out to 19 μm. Furthermore, the thing (comparative example 4) by the focusing fiber material which diameter-reduced 100 SUS304 stainless steel wires by the focusing wire drawing method was used. The focused wire drawing method is a method of bundling and drawing a single wire in which a SUS304 rod is inserted into the sheath tube, and then eluting and removing the sheath tube. About the fiber material by the focused wire drawing by the comparative example 4, the surface was rough and the cross section was indefinite shape, and toughness was also somewhat inferior. Table 2 shows the characteristics of the obtained thin wires.

(2) Twisted wire processing Next, the wire materials obtained by the above processing were twisted in the following manner. For twisting, three primary stranded wires obtained by twisting seven metal thin wires at a pitch of 4 mm using a high-speed stranded wire machine (manufactured by Haruna Iron Works Co., Ltd.) are pitched in the direction opposite to the primary stranded wire. Twisted together at 6 mm to form a secondary stranded wire, and the number of the fine metal wires in the stranded wire (preliminary focusing body) is 21 in total. In Comparative Example 4, tow, which is an aggregate of thin lines, is used as it is.

(3) Low-temperature heat treatment Each strand wire (preliminary bundling body) is passed through a tubular furnace having a furnace length of 2 m, and after tensile annealing at a temperature of 600 ° C. (speed: 10 m / min) while applying a tension of 1500 to 2000 MPa, tensile strength Table 3 shows the results obtained by examining the fatigue characteristics associated with the bending strength ratio, straightness, and repeated bending. FIG. 2 shows the change in breaking strength (N / mm ² ) and straightness in the range up to 650 ° C. by further narrowing the measurement temperature interval for Example 1, and FIG. The microscope organization in the cross section is shown magnified 400 times. Examples 1 to 4 all had a tensile strength of 3000 N / mm ² or more and were not easily broken due to bending.

  In Table 3, the tensile strength and the yield strength ratio are values obtained by dividing the strength when one metal wire is extracted from the obtained stranded wire and fractured in the tensile test by the cross-sectional area. Is a value obtained by calculating the yield strength from the stress-strain diagram at that time and using the above formula. Straightness and fatigue characteristics are the results for a stranded wire subjected to low-temperature heat treatment, and straightness is indicated by the maximum separation distance (H) (mm) when the above-described length of 1000 mm is dropped. As shown in FIG. 4, the fatigue characteristic is a test in which a measurement sample is stretched over a distance of 50 mm between chucks, one is fixed, and the other is bent 180 ° left and right repeatedly. The number of times is calculated. In the test, each 90 ° was bent at a rate of once per second, and each 90 ° was counted as one time, and the average value of three points for each sample is shown. The radius R of the bending part of the stationary jig is 1 mm.

As shown in FIG. 2, when the heat treatment is performed at a low temperature in the range of 500 to 650 ° C., a value higher than the initial strength is obtained in a low temperature range of 575 ° C. or less, but the straightness is not completely perfect but slightly inferior. On the other hand, at higher temperatures, the strength gradually decreased and the straightness tended to improve conversely, and with regard to fatigue properties, a slightly lower temperature was preferable. It is desirable to set the heat treatment conditions in consideration of such a tendency.

Next, as a performance test as a static elimination brush, what was heat-treated at 600 ° C. at low temperature was used as an electrode wire , and four types of stranded wires of Examples 1 and 3 and Comparative Examples 3 and 4 each had a length of 15 mm. What was cut into short fibers was placed on an aluminum support at intervals of 1.5 mm, and the upper surface thereof was fixed with a fixing tape, and the following test was conducted as a static elimination brush.

(Test 1: Paper endurance test)
As a durability test (life test) of the brush, a continuous paper for copying was attached to a belt sander, and this was rotated at a rotational speed of 120 sheets / min in the R direction length of the A4 plate. It was set to a height at which 3 mm contacted, and the bending deformation state of the fiber when it was continuously passed up to 5 million converted sheets was tested. Also, as a break-off test during feeding, the presence or absence of breakage was confirmed when the converging line was pressed and bent 5 million times at the same speed of 120 sheets / min as described above, contacting the paper from the support to a height of 3 mm. did. The results are shown in Table 4. For the former bending deformation, the spread width (mm) at the tip of each tip of each hair tip is obtained on a scale, and this is averaged. For the breakage result, the difference in the number of fibers before and after the test is calculated as the initial number. The occurrence rate is defined as 100 percent of the value divided by.

  As can be seen from this result, the example product has less bending deformation and the dropout (breakage) is much less than those of the other comparative examples. Although the bending deformation is not so much seen in the amorphous thin wire of Comparative Example 3, the break-off rate is as high as 16%, and the focused wire drawing material of Comparative Example 4 has a large bending deformation and a little large breaking. It was.

(Test 2: Fiber drop-out test)
It pressed against the adhesive surface of the gum tape in a state where the hair tips of each static elimination brush were in contact with each other, and the state was maintained for 10 seconds and then pulled up, and the state of generation of fibers remaining on the gum tape at that time was observed. As a result, four residual fibers were observed in Comparative Example 4, but no residual fine lines were observed for the other brushes.

It is a front view which shows one form of the static elimination brush of this invention. It is a diagram which illustrates the change of the tensile strength of the thin wire | line with the heat processing temperature, and the change of the straightness of a twisted wire. It is the microscope picture of the longitudinal direction cross section of the thin wire | line after heat processing (equivalent to 400 time at a longitudinal length of 8 cm). It is the schematic of a repeated bending fatigue tester.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Static elimination brush 2 Metal fine wire 3 Focusing wire 3A Pre-focusing wire 4 Conductive support body 5 Adhesive tape

Claims (4)

A focusing body obtained by focusing a plurality of fine metal wires having a specific resistance at room temperature of 100 μΩ · cm or less is fixed to a conductive support, and the fine metal wire has a wire diameter (d) of 0.1 mm or less and a mass. % : C: 0.06-0.12%, Si: 0.3-0.9%, Mn: 0.3-1.0%, Ni: 8.0-9.0%, Cr : 18.11 to 19.0%, Mo: 0.54 to 1.0%, N: 0.1 to 0.25% , the balance being substantially composed of inevitable impurities and Fe, Mo and N added austenite A neutralizing brush comprising a hard stainless steel wire.
  The neutralizing brush according to claim 1, wherein the thin metal wire has a Young's modulus of 125,000 to 150,000 MPa and a wire diameter of 1 to 50 µm.   The neutralizing brush according to claim 1 or 2, wherein the converging body is formed of a stranded wire obtained by twisting a plurality of the thin metal wires.   The neutralizing brush according to any one of claims 1 to 3, wherein the bundling body is subjected to low-temperature heat treatment at a temperature of 500 to 700 ° C after the twisting process and has a straightness of 30/1000 mm or less.