Nonwoven fabric for toner seals

Abstract

The present invention is a nonwoven fabric (1) for use as a toner seal material for preventing toner leakage from the outer circumferential surface at an edge portion of a rotating body carrying powdered toner in an image forming device. The surface of the nonwoven fabric (1) has recessed portions (2) and raised portions (3) extending along the length direction (4) of the nonwoven fabric. The recessed portions (2) are groove-shaped recessed portions. The constituent fibers (6) have an average fiber diameter of 14.0 μm or less. The orientation of the constituent fibers (6) of the nonwoven fabric (1) is orthogonal or inclined with respect to the length direction (4) of the nonwoven fabric (1). The constituent fibers (6) are not heat-fused to each other. The angle of the orientation of the constituent fibers (6) with respect to the length direction (4) of the nonwoven fabric (1) is preferably 45°-135°.

Description

[Technical Field]

[0001] The present invention relates to a nonwoven fabric for a toner seal, which prevents leakage of toner from the outer peripheral surface of a rotating body that carries powder toner in an electrophotographic image forming device in the axial direction of the rotating body, a method for manufacturing the same, and a toner seal material that includes the nonwoven fabric for a toner seal. [Background technology]

[0002] Traditionally, electrophotographic image forming devices have used powder toner as a developer. Electrophotographic image forming devices are widely used in printers, copiers, facsimile machines, and the like. In electrophotography, an electrostatic latent image is formed on an image carrier such as a photosensitive drum, developed with toner, and then transferred to a recording sheet or the like, where the toner is fixed to the recording sheet or the like. The toner is stored in a container (toner box) of the development unit and moves to the surface of the photosensitive drum or the like while adhering to the outer surface of the development roller. As the development roller or photosensitive drum rotates, the toner adheres to its outer surface. The development roller or photosensitive drum is provided with a sealant to prevent toner from leaking, for example, outward in the axial direction.

[0003] As prior art related to a sealing material for preventing leakage of fine powder or granular material, Patent Document 1 proposes a cut pile fabric including a pile that contacts the surface of a movable body and a base fabric that supports the pile. Patent Documents 2 and 3 propose the use of a nonwoven fabric as a sealing material. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-249383 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-076145 [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-164064 Summary of the Invention [Problem to be solved by the invention]

[0005] However, there still remains a problem that the toner leaks from the outer circumferential surface of the rotating body that carries the powder toner in the axial direction.

[0006] In order to solve the above problems, the present invention provides a nonwoven fabric for toner seals that can effectively prevent toner leakage in the axial direction from the outer peripheral surface of a rotating body that carries powdered toner, a method for manufacturing the same, and a toner seal material that includes the nonwoven fabric for toner seals. [Means for solving the problem]

[0007] In one aspect, the present invention provides a nonwoven fabric for a toner seal material for preventing leakage of toner from an outer peripheral surface of an end portion of a rotating body that carries powder toner in an image forming apparatus, the nonwoven fabric comprising: The surface of the nonwoven fabric has recesses and protrusions extending along the length direction of the nonwoven fabric, and the recesses are groove-like recesses; The orientation of the constituent fibers of the nonwoven fabric is perpendicular or inclined to the longitudinal direction of the nonwoven fabric, The average fiber diameter of the constituent fibers is 14.0 μm or less, The present invention relates to a nonwoven fabric for a toner seal, in which the constituent fibers are not thermally fused together.

[0008] In one aspect, the present invention provides a toner seal material comprising the nonwoven fabric for a toner seal of the present invention and a cushion layer laminated on one main surface of the nonwoven fabric for a toner seal, the recessed portion and the protruding portion are provided on a surface of the nonwoven fabric for a toner seal opposite to the surface on the cushion layer side, The longitudinal direction of the recessed portion and the protruding portion is aligned with the longitudinal direction of the toner seal material.

[0009] In one aspect, the present invention relates to a method for producing a nonwoven fabric for a toner seal, which method includes the following steps A to C. A. A process for producing a long fiber web in which short fibers having an average fiber diameter of 14.0 μm or less are oriented in the longitudinal direction. B. A step of cross-lapping the fiber web to prepare a long laminated web. C. A step of forming depressions and protrusions on the surface of the laminated web by spraying a pressurized water stream from a spray nozzle along the length direction of the laminated web. [Effects of the Invention]

[0010] The nonwoven fabric for toner seals of the present invention is a nonwoven fabric for use in toner seal materials. The average fiber diameter of the constituent fibers is 14.0 μm or less, and the constituent fibers are not thermally fused to each other. The surface of the nonwoven fabric has concave and convex portions extending along its length. The concave portions are groove-like, so when a toner seal material including the nonwoven fabric is attached to a rotating body, the length of the groove-like recesses is the same as the circumferential direction of the rotating body. Furthermore, the constituent fibers of the nonwoven fabric are oriented perpendicular or inclined to the length of the nonwoven fabric. Therefore, when the toner seal material is attached to a rotating body, the constituent fibers are oriented perpendicular or inclined to the circumferential direction of the rotating body. As a result, the nonwoven fabric for toner seals of the present invention has a larger surface area facing the rotating body than nonwoven fabrics without a concave-convex structure, and because the constituent fibers are not thermally fused to each other, the surface has a larger number of pores. As a result, the pores can capture and firmly hold toner moving at the interface between the rotating body and the nonwoven fabric, preventing the toner from moving toward the ends of the rotating body. In addition, the fibers that are perpendicular or inclined to the circumferential direction of the rotating body prevent the toner from moving toward the ends of the rotating body. Therefore, by using the nonwoven fabric for toner seals of the present invention, the toner trapping rate of the toner seal material is high, and toner leakage can be effectively prevented. Furthermore, the nonwoven fabric has an average fiber diameter of 14.0 μm or less for the constituent fibers, has the recesses and protrusions on the surface of the nonwoven fabric facing the rotating body, and the length direction of the recesses is the same as the circumferential direction of the rotating body, thereby reducing the frictional resistance between the nonwoven fabric and the rotating body, and is advantageous in reducing the load on the motor of the image forming device. [Brief explanation of the drawings]

[0011] [Figure 1A] FIG. 1A is a schematic perspective view of a nonwoven fabric for a toner seal according to one embodiment of the present invention. [Figure 1B] FIG. 1B is a schematic cross-sectional view taken along line II in FIG. 1A. [Figure 2] FIG. 2 is a schematic explanatory view showing the step of producing a laminated web in the method for producing a nonwoven fabric for a toner seal according to one embodiment of the present invention. [Figure 3] FIG. 3 is a schematic plan view of a part of the fiber web during folding. [Figure 4] FIG. 4 is a schematic explanatory view illustrating the state in which a pressurized water stream is sprayed onto a laminated web in a method for producing a nonwoven fabric for a toner seal according to one embodiment of the present invention. [Figure 5] FIG. 5 is a schematic exploded perspective view showing a state in which a toner seal material according to one embodiment of the present invention is attached to the outer peripheral surface of the end portion of a developing roller. [Figure 6A] FIG. 6A is a schematic perspective view of a toner sealing material according to one embodiment of the present invention. [Figure 6B] FIG. 6B is a schematic cross-sectional view taken along line VI-VI in FIG. 6A. [Figure 7A] FIG. 7A is an enlarged plan view of the nonwoven fabric for a toner seal of Example 1. [Figure 7B] FIG. 7B is an enlarged cross-sectional view of the nonwoven fabric for a toner seal of Example 1, as viewed in the same direction as its length. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Nonwoven fabric for toner seals] The nonwoven fabric for toner seals (hereinafter sometimes abbreviated as "nonwoven fabric") of the present invention is a nonwoven fabric constituting a toner seal material for preventing toner leakage from the outer peripheral surface of the end of a rotating body that carries powdered toner in an image forming apparatus in the axial direction of the rotating body. The surface of the nonwoven fabric has recesses and protrusions extending along its length. The recesses are groove-like recesses. The orientation of the constituent fibers of the nonwoven fabric is perpendicular or inclined to the length direction of the nonwoven fabric. The average fiber diameter of the constituent fibers of the nonwoven fabric is 14.0 μm or less, and the constituent fibers are not thermally fused to each other. Furthermore, the length direction of the nonwoven fabric is the same as the longitudinal direction of the toner seal material, and the longitudinal direction of the toner seal material is the same as the circumferential direction of the rotating body when the toner seal material is attached to a rotating body that carries powder toner in an image forming device.

[0013] The groove-like depressions can be formed by spraying a pressurized water stream onto a long laminated web. The spaces between the groove-like depressions become convex portions, so that the surface of the nonwoven fabric has a striped pattern of groove-like depressions and convex stripes extending in the longitudinal direction. A structure in which the constituent fibers of a nonwoven fabric are oriented perpendicular or inclined to the longitudinal direction of the sealing material can be formed by laminating a fiber web using a folding method called cross-wrapping. The groove-like recesses are formed by spraying pressurized water onto the laminated web, and the constituent fibers are also entangled. This entanglement of the constituent fibers improves the integrity of the nonwoven fabric.

[0014] The phrase "orthogonal or inclined" to the longitudinal direction of the nonwoven fabric means excluding cases where the orientation of the constituent fibers of the nonwoven fabric is substantially parallel to the longitudinal direction of the nonwoven fabric, and more specifically, excludes nonwoven fabrics manufactured using parallel webs as a long laminate web. Here, "substantially parallel" not only means completely parallel, but also includes cases where the orientation of the constituent fibers is at an angle of 0 to 30° to the longitudinal direction of the nonwoven fabric.

[0015] The angle of the orientation of the constituent fibers (the length direction of the constituent fibers) with respect to the length direction of the nonwoven fabric is preferably 45° to 135°, more preferably 55° to 125°, even more preferably 65° to 115°, and even more preferably 70° to 110°. By having the orientation of the constituent fibers perpendicular or inclined to the length direction of the nonwoven fabric (the length direction of the groove-like recesses) in this way, the toner trapping rate is higher than when, for example, the length direction of the groove-like recesses and the orientation of the constituent fibers are the same, and toner leakage can be effectively prevented.

[0016] The constituent fibers of the nonwoven fabric are preferably short fibers. The average fiber diameter of the constituent fibers is 14.0 μm or less, more preferably 12.5 μm or less, and even more preferably 10.0 μm or less. This provides high strength, effectively prevents toner leakage, and is advantageous in terms of smoothing the surface of the nonwoven fabric that contacts the rotating body and reducing frictional resistance between the nonwoven fabric and the sealing material. The lower limit of the average fiber diameter of the constituent fibers is preferably 1.0 μm or more, more preferably 3.0 μm or more, and even more preferably 5.0 μm or more. This allows the toner to be caught and firmly held by the non-penetrating pores on the surface of the nonwoven fabric. The nonwoven fabric may contain two or more types of constituent fibers with different average fiber diameters. In the present application, the average fiber diameter of the constituent fibers of the nonwoven fabric is the average value obtained by observing the fibers with a microscope (VHX-600, manufactured by Keyence) and measuring the diameters of 100 randomly selected constituent fibers.

[0017] The average fiber length of the constituent fibers is preferably 30 to 110 mm, more preferably 35 to 90 mm, and even more preferably 40 to 70 mm, which allows efficient production of a fiber web using a standard carding machine. In the present application, the average fiber length of the constituent fibers of the nonwoven fabric is the average value of the lengths of 100 randomly selected constituent fibers measured with a steel ruler.

[0018] The average widthwise pitch P (see FIG. 1B) of the groove-like recesses is preferably 0.3 to 3.0 mm, more preferably 0.6 to 2.8 mm, and even more preferably 0.7 to 2.5 mm, from the viewpoint of effectively preventing toner leakage. The pitch is the distance between the apexes of adjacent protrusions. From the viewpoint of effectively preventing toner leakage, the average depth D of the groove-like recesses (see FIG. 1B) is preferably 5 to 30%, more preferably 10 to 28%, and even more preferably 10 to 25% of the average thickness H of the nonwoven fabric (see FIG. 1B). This increases the toner trapping rate, making it possible to effectively prevent toner leakage. The thickness of the nonwoven fabric is the thickness at the protrusions.

[0019] The average thickness H of the nonwoven fabric is preferably 0.3 to 3.0 mm, more preferably 0.5 to 2.0 mm, and even more preferably 0.5 to 1.5 mm, which makes it easier to incorporate the toner sealing material containing the nonwoven fabric into an image forming apparatus (printer).

[0020] In the present application, the average pitch P, average depth D, and average thickness H are each the average values ​​obtained by observing and measuring 20 randomly selected points using a microscope (VHX-600, manufactured by Keyence Corporation).

[0021] The mass per unit area of ​​the nonwoven fabric is preferably 80 to 600 g / m from the viewpoint of effectively preventing toner leakage. 2 , more preferably 100 to 500 g / m 2 , and more preferably 100 to 450 g / m 2 is.

[0022] There are no particular restrictions on the material of the constituent fibers of the nonwoven fabric, but it is preferable that the nonwoven fabric contains, for example, polyester staple fibers. Polyester staple fibers have the advantage of being strong and not easily generating debris even when rubbed against a rotating body. A preferred example of polyester staple fibers is polyethylene terephthalate (PET) staple fibers. The nonwoven fabric may also contain two or more constituent fibers made of different materials.

[0023] [Method of manufacturing nonwoven fabric for toner seals] In one embodiment, the method for producing a nonwoven fabric for a toner seal of the present invention includes the following steps A to C. A. A process for producing a long fiber web in which short fibers having an average fiber diameter of 14.0 μm or less are oriented in the longitudinal direction. B. A step of cross-lapping the fiber web to prepare a long laminated web. C. A step of forming recesses and protrusions on the surface of the laminated web by spraying a pressurized water stream from a spray nozzle along the length direction of the laminated web.

[0024] In the above step A, staple fibers are opened to produce a fiber web in which the orientation (length direction) of the staple fibers is oriented in the length direction. In the above step A, for example, it is efficient and preferable to open the staple fibers and align the orientation of the staple fibers using a carding machine. The mass per unit area of ​​the fiber web is 8 to 40 g / m 2 is preferred.

[0025] In step B, for example, a device called a cross wrapper is used to fold (cross wrap) a long fiber web multiple times as shown in Fig. 3 to form a long laminate web (also called a cross web). An example of a method for manufacturing a cross web is disclosed in JP-A-6-116853, etc. In the laminate web, the direction (length direction) of the short fibers is perpendicular or inclined to the length direction of the laminate web.

[0026] In step C, a pressurized water stream is sprayed onto the laminated web from a spray nozzle. This process is also called a water jet process. This process entangles the constituent fibers and forms recesses and protrusions on the surface of the laminated web. The pressure of the water stream is preferably 0.5 to 20 MPa. Furthermore, before applying the pressurized water stream to the laminated web, it is preferable to perform a needle punching process to entangle the short fibers. This improves the handleability of the nonwoven fabric. When the short fibers are entangled by applying a pressurized water stream or needle punching, the pores of the nonwoven fabric are not reduced by thermal fusion, as occurs when the constituent fibers are bonded by a thermal bonding process, resulting in a decrease in pore size. When the short fibers are entangled by applying a pressurized water stream or needle punching, this process has the advantage of capturing toner that has migrated from the surface of the rotating body with the pores, thereby enabling the toner to be firmly retained.

[0027] The following description will be given with reference to the drawings, in which the same reference numerals denote the same parts. Fig. 1A is a schematic perspective view of a nonwoven fabric 1 for a toner seal according to one embodiment of the present invention, and Fig. 1B is a schematic cross-sectional view taken along line II in Fig. 1A. On one surface of this nonwoven fabric 1, recesses 2 and protrusions 3 facing in the length direction 4 are alternately repeated along the width direction 5 of the nonwoven fabric 1. The orientation (length direction) of the constituent fibers 6 is oriented in the width direction 5 of the nonwoven fabric 1. The constituent fibers 6 are also entangled, maintaining the integrity of the nonwoven fabric 1. From the viewpoint of application to a rotating body that carries powdered toner in an image forming apparatus, the nonwoven fabric 1 for a toner seal preferably has a length of 10 to 50 mm and a width of 3 to 15 mm.

[0028] FIG. 2 is a schematic explanatory diagram showing the step of producing a laminated web in the method of producing a nonwoven fabric 1 for toner seals according to one embodiment of the present invention, and FIG. 3 is a schematic plan view of a portion of a fiber web in the process of being folded. In Fig. 2, reference numeral 11 denotes a carding machine, into which unopened staple fibers 12 are fed from feed rollers 13a and 13b. The unopened staple fibers 12 pass through a take-in roller 14 and are opened by the cooperation of a cylinder 15, workers 16a and 17a, and strippers 16b and 17b. The opened staple fibers 12 then pass through a doffer 18 and are stripped from the doffer 18 by a vibration comb 19, and are taken out as a fiber web 20. Reference numeral 21 denotes a base of the carding machine.

[0029] 2, the fiber web 20 is folded multiple times toward the front or rear on the operating conveying means (take-up device) 23 to form a long laminated web 22. More specifically, since the fiber web 20 is folded toward the front or rear on the operating conveying means 23, a relatively upper portion of the fiber web 20 protrudes from a relatively lower portion, as shown in FIG. 3, and this is repeated multiple times to obtain a long laminated web 22 (cross web). Thereafter, the laminated web 22 may be needle-punched along its longitudinal direction to entangle the constituent fibers before applying a pressurized water stream, which will be described later.

[0030] FIG. 4 is a schematic explanatory view illustrating the state in which a pressurized water stream is sprayed onto a laminated web in a method for producing a nonwoven fabric for a toner seal according to one embodiment of the present invention. In Figure 4, reference numeral 24 denotes a water jet device. A pressurized water stream is sprayed from a spray nozzle 26 onto the laminated web 22 unwound from a roll 25 of the laminated web 22, and the laminated web 22 is then dried in a drying device 27 and rolled up to form a roll 28. The rolled nonwoven fabric sheet preferably has a length of 10 to 100 m and a width of 30 to 240 cm, for example.

[0031] FIG. 5 is a schematic exploded perspective view showing a state in which a toner seal material containing a nonwoven fabric for a toner seal according to one embodiment of the present invention is attached to the outer peripheral surface of an end portion of a developing roller. Toner seal materials 32a and 32b, which prevent leakage of fine powder particles, function as side seals on both ends 33a and 33b of developing roller 33. These toner seal materials 32a and 32b are in close contact with the outer circumferential surface of developing roller 33 and are arranged to prevent toner from leaking outward in the direction of axis 34a. Developing roller 33 is attached to opening 37 facing developing roller 33 in developing unit 31 of an electrophotographic image forming apparatus.

[0032] Toner seal materials 32a and 32b are attached to a housing 35 of the developing unit 31 before the developing roller 33. The developing unit 31 is also provided with a blade 36. The thickness of the toner layer is adjusted by the blade 36, which is a toner regulating member, and is kept below a certain level. A rotating shaft 34 of the developing roller 33 is rotatably supported by the housing 35 of the developing unit 31, and toner is supplied to the developing roller 33 from inside the developing unit 31.

[0033] [Toner sealant] As shown in FIG. 6, the toner seal material 32 of the present invention includes, for example, the nonwoven fabric 1 for a toner seal of the present invention and a cushion layer 38 laminated on one main surface of the nonwoven fabric 1 for a toner seal. The cushion layer 38 contacts one of the two main surfaces of the nonwoven fabric 1 opposite the surface including the recessed portions 2 and the protruding portions 3. The nonwoven fabric 1 and the cushion layer 38 are bonded together using, for example, an adhesive. The longitudinal direction of the recessed portions 2 and the protruding portions 3 is aligned with the longitudinal direction of the toner seal material 32. From the viewpoint of application to a rotating body that carries powdered toner in an image forming apparatus, the toner seal material 32 preferably has a length of 10 to 50 mm and a width of 3 to 15 mm.

[0034] There are no particular limitations on the cushion layer 38, as long as it is an elastic body such as a resin sheet or a relatively elastic nonwoven fabric, etc. The cushion layer 38 is preferably a foam such as urethane foam, since it needs to be flexible enough to prevent wrinkles when the toner seal material 32 is attached to the rotating body and bent, for example, into a U-shape along the circumferential direction of the rotating body.

[0035] The thickness of the cushion layer 38 may be set in consideration of the thickness of the nonwoven fabric 1 for toner seal so that the total thickness of the toner seal material 32 is 2.0 to 5.0 mm, but is preferably 0.5 to 4.0 mm, more preferably 0.5 to 3.0 mm, and even more preferably 0.5 to 2.0 mm. This makes it easier to incorporate the toner seal material 32 into the image forming device (printer).

[0036] In this specification, the upper and lower limits of each numerical range can be combined in any combination, and all such combinations are considered to be preferred numerical ranges described in this specification. [Example]

[0037] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The physical properties in the examples were measured by methods commonly used in the textile industry. In the examples, "parts" and "%" are based on mass. The following examples and comparative examples were evaluated as follows.

[0038] [Dynamic friction coefficient] The coefficient of dynamic friction of the nonwoven fabrics for toner seals of Example 1 and Comparative Example 1 below was measured in accordance with JIS K 7125:1999. Specifically, an acrylic plate was placed on a test table with a horizontal and smooth surface, and the nonwoven fabric for toner seals, a sliding piece with felt attached to its bottom, and a weight (200 g) were placed on top of it in that order. A cable was attached to the nonwoven fabric for toner seals, and the cable was pulled horizontally with a load cell at a test speed of 100 mm / min to measure the coefficient of dynamic friction.

[0039] [Toner leakage test] A urethane foam (PORON LE20, 2 mm thick, manufactured by Inoac Corporation) was attached as a cushioning layer to one main surface of the nonwoven fabric for toner seals of Example 2 and Comparative Examples 2 to 4 to produce toner seal materials with a total thickness of 3 mm. Using color toner with a particle size of approximately 8 μm, the penetration rate (%) of the toner in the width direction (direction of arrow 7 in Figure 5) of the nonwoven fabric for toner seals was measured after printing 5,000 A4-sized sheets. A higher penetration rate (%) indicates a higher likelihood of toner leakage, while a lower value indicates more effective suppression of toner leakage. The penetration rate (%) of the toner is the ratio of the length up to the point where the toner reaches to the total width of the nonwoven fabric for toner seals, assuming the total width of the nonwoven fabric for toner seals to be 100.

[0040] Example 1 Polyethylene terephthalate (Toray) staple fibers with an average fiber diameter of 9.0 μm (fineness 0.9 decitex) and an average fiber length of 51 mm were opened using a carding machine as shown in Figure 2 to produce a long fiber web in which the PET staple fibers were oriented in the longitudinal direction. The mass per unit area of ​​the fiber web (basis weight) was 30 g / m. 2 Next, the fiber web was cross-wrapped to produce a long laminated web (cross web). The orientation of the short fibers was 80 to 100° relative to the longitudinal direction of the laminated web. Next, as shown in Figure 4, a pressurized water stream (8 MPa) was sprayed from a spray nozzle along the longitudinal direction of the laminated web. The areas hit by the water stream formed recesses, and the areas not hit by the water stream formed protrusions. One surface of the obtained nonwoven fabric sheet was as shown in Figures 1A and 1B. The mass per unit area of ​​the obtained nonwoven fabric sheet (basis weight) was 300 g / m 2 The thickness of the convex portions was approximately 1.0 mm, the average pitch of the concave portions in the width direction was approximately 1.5 mm, and the depth of the concave portions was approximately 200 μm. This nonwoven fabric sheet was cut into a length of 40 mm and a width of 10 mm to obtain a nonwoven fabric for a toner seal. Figure 7A shows an enlarged planar photograph (100x magnification) of the nonwoven fabric for a toner seal of Example 1, and Figure 7B shows an enlarged cross-sectional view (100x magnification) of the nonwoven fabric for a toner seal of Example 1 as viewed in the same direction as its length.

[0041] (Comparative Example 1) A nonwoven fabric sheet was produced in the same manner as in Example 1, except that polyethylene terephthalate (manufactured by Toray) staple fibers with an average fiber diameter of 14.5 μm (fineness 2.2 decitex) and an average fiber length of 51 mm were used as the short fibers. The mass per unit area of ​​the fiber web (basis weight) is 30 g / m 2 It was decided. The orientation of the short fibers was 80 to 100° to the longitudinal direction of the nonwoven fabric sheet. The mass per unit area (basis weight) of the nonwoven fabric sheet was 300 g / m 2 The thickness of the convex portions was 1.0 mm, the average pitch of the concave portions in the width direction was 1.5 mm, and the depth of the concave portions was 200 μm. This nonwoven fabric sheet was cut into a length of 40 mm and a width of 10 mm to obtain a nonwoven fabric for a toner seal.

[0042] Example 2 A nonwoven fabric sheet was produced in the same manner as in Example 1, except that the following two types of short fibers were used. (1) 70% by mass of polyethylene terephthalate (Toray) short fibers with an average fiber diameter of 9.0 μm (fineness 0.9 decitex) and an average fiber length of 51 mm (2) 30% by mass of heat-fusible short fibers (core: polyethylene terephthalate, sheath: polyethylene, manufactured by Toray) with an average fiber diameter of 20.2 μm (fineness 4.4 decitex) and an average fiber length of 51 mm The average fiber diameter of the two types of short fibers is 12.4 μm (fineness 1.95 decitex). The mass per unit area of ​​the fiber web (basis weight) is 30 g / m 2 It was decided. The orientation of the short fibers was 80 to 100° to the longitudinal direction of the nonwoven fabric sheet. The mass per unit area (basis weight) of the nonwoven fabric sheet was 300 g / m 2 The thickness of the convex portions was 1.0 mm, the average pitch of the concave portions in the width direction was 1.5 mm, and the depth of the concave portions was 200 μm. This nonwoven fabric sheet was cut into a length of 40 mm and a width of 10 mm to obtain a nonwoven fabric for a toner seal.

[0043] (Comparative Example 2) A long laminated web (cross web) was produced in the same manner as in Example 2, using the same two types of staple fibers in the same proportions. The laminated web was then needle-punched to push some of the staple fibers into the web, and then brought into contact with a heated roll having an uneven surface to heat-seal the heat-fusible staple fibers, thereby obtaining a nonwoven fabric sheet. The orientation of the short fibers was 80 to 100° to the longitudinal direction of the nonwoven fabric sheet. The mass per unit area (basis weight) of the nonwoven fabric sheet was 300 g / m 2 The thickness of the convex portions was 1.0 mm, the average pitch of the concave portions in the width direction was 1.5 mm, and the depth of the concave portions was 250 μm. This nonwoven fabric sheet was cut into a length of 40 mm and a width of 10 mm to obtain a nonwoven fabric for a toner seal.

[0044] (Comparative Example 3) A long laminated web (cross web) was produced in the same manner as in Example 2, using the same two types of staple fibers in the same proportions as in Example 2. The laminated web was then needle-punched to push some of the staple fibers into the web, and then passed through a calender to smooth the surface. The orientation of the short fibers was 80 to 100° to the longitudinal direction of the nonwoven fabric sheet. The mass per unit area (basis weight) of the nonwoven fabric sheet was 300 g / m 2 The nonwoven fabric sheet was cut into a length of 40 mm and a width of 10 mm to obtain a nonwoven fabric for a toner seal.

[0045] Comparative Example 4 Using the same staple fibers as in Example 1, a fiber web was produced and wound up in the same manner as in Example 1. Next, the fiber webs were stacked in parallel to produce a long laminated web. Thereafter, a pressurized water stream (8 MPa) was sprayed from a spray nozzle along the length of the laminated web, as shown in Figure 4. The portions hit by the water stream formed recesses, and the portions not hit by the water stream formed protrusions. The orientation of the short fibers was 0 to 10° with respect to the length direction of the nonwoven fabric sheet and was substantially parallel to the length direction of the nonwoven fabric sheet. The mass per unit area (basis weight) of the nonwoven fabric sheet was 300 g / m 2The thickness of the convex portions was 1.0 mm, the average pitch of the concave portions in the width direction was 1.5 mm, and the depth of the concave portions was 200 μm. This nonwoven fabric sheet was cut into a length of 40 mm and a width of 10 mm to obtain a nonwoven fabric for a toner seal.

[0046] Table 1 below summarizes the results of evaluating the coefficient of dynamic friction and the degree of toner penetration according to the method described in the above [Toner Leakage Test] for the Examples and Comparative Examples.

[0047] [Table 1]

[0048] As shown in Table 1, the dynamic friction coefficients of the nonwoven fabrics for toner seals of Example 1 and Comparative Example 1 were 0.25 and 0.30, respectively. From these results, it was confirmed that the nonwoven fabric for toner seals of Example 1 has lower friction and better sliding properties than the nonwoven fabric for toner seals of Comparative Example 1, and contributes to reducing the load on the motor. Furthermore, it was confirmed that toner leakage can be effectively suppressed when the average fiber diameter of the constituent fibers is 14.0 μm or less, the constituent fibers are not thermally fused together, the surface of the nonwoven fabric has recesses and protrusions extending along its length, the angle of the constituent fibers is perpendicular or inclined to the longitudinal direction of the groove-shaped recesses, and the orientation (angle) of the constituent fibers with respect to the longitudinal direction of the recesses is, for example, 45° to 135°. [Industrial Applicability]

[0049] The nonwoven fabric for toner seals of the present invention is useful as a material for sealing materials to prevent leakage of toner from electrophotographic image forming apparatuses that use powder toner. [Explanation of symbols]

[0050] 1 Nonwoven fabric for toner seals 2 Groove-shaped recess (recess) 3 Convex part 4 Lengthwise direction of nonwoven fabric for toner seal 5 Width direction of nonwoven fabric for toner seal 6. Constituent Fibers 11 Card machine 12 Unopened short fibers 13a, 13b Feed rollers 14 Tekain Roller 15 cylinders 16a,17a Worker 16b,17b Stripper 18 Dohwa 19 Vibration Comb 20 Fiber Web 21 Card machine base 22 Laminated Web 23 Removal device 24 Water jet equipment 25,28 Winding body 26 Injection nozzle 27 Drying equipment 31 Development unit 33 Developing roller 32, 32a, 32b Toner seal material 33a, 33b Both ends of the developing roller 34 Rotation axis 34a axis 35 Housing 36 blades 38 Cushion layer

Claims

1. A nonwoven fabric for a toner seal material for preventing leakage of toner from the outer peripheral surface of an end portion of a rotating body that carries powder toner in an image forming apparatus, The nonwoven fabric is formed by laminating long fiber webs in a cross-wrapped and folded state, the surface of the nonwoven fabric has recesses and protrusions extending along the length direction of the nonwoven fabric, the recesses are groove-like recesses, the average pitch of the groove-like recesses in the width direction is 0.6 to 2.8 mm, and at least some of the fibers in the groove-like recesses are entangled; The orientation of the constituent fibers of the nonwoven fabric is 65° to 115° with respect to the longitudinal direction of the nonwoven fabric, The average fiber diameter of the constituent fibers is 3.0 μm or more and 14.0 μm or less, The nonwoven fabric for a toner seal has constituent fibers that are not thermally fused together.

2. 2. The nonwoven fabric for a toner seal according to claim 1, wherein the constituent fibers include short fibers having an average fiber length of 30 to 110 mm.

3. 2. The nonwoven fabric for a toner seal according to claim 1, wherein the average depth of the groove-like recesses is 5 to 30% of the average thickness of the nonwoven fabric from the surface.

4. The mass per unit area of ​​the nonwoven fabric is 80 to 600 g / m 2 2. The nonwoven fabric for a toner seal according to claim 1, wherein

5. 2. The nonwoven fabric for a toner seal according to claim 1, wherein the thickness of the nonwoven fabric is 0.3 to 3.0 mm.

6. 2. The nonwoven fabric for a toner seal according to claim 1, wherein the nonwoven fabric is made of polyester staple fibers.

7. A toner seal material comprising the nonwoven fabric for a toner seal according to any one of claims 1 to 6 and a cushion layer laminated on one main surface of the nonwoven fabric for a toner seal, the recessed portion and the protruding portion are provided on a surface of the nonwoven fabric for a toner seal opposite to the surface on the cushion layer side, The longitudinal direction of the recessed portion and the protruding portion is aligned with the longitudinal direction of the toner seal material.

8. A method for producing the nonwoven fabric for a toner seal according to any one of claims 1 to 6, comprising the following steps A to C: A. A process for producing a long fiber web in which short fibers having an average fiber diameter of 3.0 μm or more and 14.0 μm or less are oriented in the longitudinal direction. B. A step of cross-lapping the fiber web to prepare a continuous laminated web. C. A step of forming recesses and protrusions on the surface of the laminated web by spraying a pressurized water stream from a spray nozzle along the length direction of the laminated web.

9. The method for producing a nonwoven fabric for a toner seal according to claim 8 , wherein the laminated web is subjected to a needle punching treatment to entangle the short fibers before applying the pressurized water stream.

10. In the step B, the mass per unit area of ​​the laminated web is 80 to 600 g / m 2 The method for producing a nonwoven fabric for a toner seal according to claim 8, wherein the cross-wrapping is performed so that the cross-wrapping is performed in a manner such ...

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