Wiping cloth, method for producing wiping cloth, wiping tape, method for producing wiping tape, and heat cutting device for wiping tape

Abstract

This wiping cloth comprises a fiber structure using polyamide ultrafine fibers, wherein: the single yarn fineness of the polyamide ultrafine fibers is at most 0.7 dtex; the content of the polyamide ultrafine fibers in the entire wiping cloth is at least 40 mass%; and the average value of the number of airborne particles having a diameter of at least 1 μm is at most 10 particles / cm2. This wiping tape has the number of liquid-borne particles having a size of at least 0.2 μm of at most 5 particles / ml / cm2 when immersed in pure water in a class 100 environment for 12 hours. Moreover, this method for producing a wiping tape is characterized by heat-cutting a fabric for a wiping tape in a clean room, and suctioning, using a suction nozzle, smoke generated by the heat cutting immediately after the heat cutting.

Description

Wiping cloth, method for manufacturing a wiping cloth, wiping tape, method for manufacturing a wiping tape, and heat-cutting device for wiping tape.

[0001] The present invention relates to a wiping cloth suitable for cleaning media in magnetic recording media such as hard disks, a method for manufacturing a wiping cloth, a wiping tape, a method for manufacturing a wiping tape, and a heat-cutting device for a wiping tape. This application claims priority under Japanese Patent Application No. 2024-171895 filed on September 30, 2024, and Japanese Patent Application No. 2024-179512 filed on October 14, 2024, and incorporates all the provisions of the said Japanese Patent Applications.

[0002] Traditionally, for cleaning media in magnetic recording media such as hard disks, woven fabrics made of ultrafine fibers have been widely used as wiping tapes.

[0003] For the weft threads in the wiping direction (perpendicular to the direction of travel), split fibers are almost always used, which are obtained by chemically or physically splitting polyester single yarns or composite fibers consisting mainly of polyester / polyamide composition.

[0004] Compared to polyamides, polyester has superior dimensional stability, generates fewer oligomers and attracts less dust, and has excellent processability in dyeing vats. For these reasons, polyester fibers are preferred for wiping tapes, and many wiping tapes contain 60% or more polyester by mass.

[0005] Although polyamide is inferior to polyester in the above respects, it has high abrasion resistance, resulting in less particle generation due to friction during media wiping. While the use of polyamide is desirable in that it generates fewer particles, polyamide is prone to contamination by oligomers, etc. (hereinafter sometimes referred to as contamination). Since a lot of contamination can damage the media during wiping, it was necessary to reduce contamination.

[0006] As a means of reducing contamination, it has been proposed to use fibers that do not contain matting agents such as titanium dioxide in the weft or warp threads to make a wiping tape (Patent Document 1).

[0007] In tapes used for wiping precision equipment such as hard disks and other magnetic recording media, wiping tapes made of high-density woven fabrics using polyester or nylon fibers are used (Patent Documents 1-4). In recent years, there has been an increasing demand for high-performance precision equipment, and therefore, there is an increasing demand for higher wiping performance in the wiping tapes used to wipe them.

[0008] To address these issues, for example, Patent Document 2 proposes a woven wiper for wiping the perpendicular magnetic recording layer or topcoat layer of a magnetic recording medium using split yarn of polyester and polyamide, characterized in that the average number of airborne particles with a diameter of 0.5 μm or more is 100 or less.

[0009] Furthermore, Patent Document 3 proposes a woven wiper for the perpendicular magnetic recording layer or topcoat layer of a magnetic recording medium, in which the warp or weft threads contain polyamide multifilaments, and the coverage ratio of the warp or weft threads present on the surface of the woven wiper to the intersecting weft or warp threads is 6:4 to 9.5:0.5, and it is stated that it is preferable to use one in which the average value of the number of liquid particles of 0.3 μm or larger is 100 or less.

[0010] Furthermore, Patent Document 4 proposes a wiping tape made of a fabric using multifilament yarns made of ultrafine fibers with a fineness of 1 denier or less as at least one of the warp or weft threads, characterized in that the ratio of the total fineness of the warp and weft threads is 1.5 to 10 times, and the total fineness of the multifilament yarns made of ultrafine fibers is greater. Patent Document 4 states that the dust generation amount of the wiping tape according to JIS B9923 6.2 (1.1) is 20 particles / ft of 5 μm or larger. ３ 100cm ２ The following has been disclosed:

[0011] Furthermore, Patent Document 1 proposes a woven wiper for wiping the perpendicular magnetic recording layer or top coat layer of a magnetic recording medium, wherein the warp and weft threads are made of long fiber yarns made of polyester and / or polyamide and / or split fiber yarns that have not been chemically split, and the woven surface of the woven wiper is characterized in that the coverage ratio of the warp and weft threads is 6:4 to 9.5:0.5, and the average number of liquid particles with a diameter of 0.3 μm or more is 100 or less.

[0012] Furthermore, Patent Documents 1 to 4 describe using heat cutting when manufacturing the tape and using pure water in the dyeing process in order to improve cleanliness.

[0013] Japanese Patent Publication No. 2017-147017, Japanese Patent Publication No. 5463648, Japanese Patent Publication No. 2022-12698, Japanese Patent Publication No. 11-9540

[0014] Patent Document 1 states that long fibers or split fibers that have not undergone chemical splitting treatment are used as fibers that do not contain the matting agent, but the specific examples given are long fibers, not split fibers. The long fibers used in the examples of Patent Document 1 have a thick single-fiber fineness and a round fiber cross-section, so their wiping performance is insufficient. Furthermore, Patent Document 1 also mentions split fibers that have been split by heat treatment, a physical splitting process after weaving, due to differences in shrinkage rates, as split fibers that have not undergone chemical splitting treatment. However, split fibers obtained by physical splitting treatment may develop a thin peeling film at the split portion, causing self-dusting and worsening the cleanliness.

[0015] The present invention has been made in view of the above-mentioned background art, and one of its objectives is to provide a wiping cloth suitable for media cleaning applications that suppresses the increase of particles due to friction during wiping, prevents contamination problems, has high wiping performance, and leaves few residues.

[0016] Furthermore, for wiping tapes used in cleanrooms, it is required to minimize contamination from the wiping tape itself, and currently, there is a need to further improve the cleanliness of the wiping tape itself.

[0017] Therefore, one of the objectives of the present invention is to solve the above-mentioned problems and provide a wiping tape and a method for manufacturing a wiping tape that have superior cleanliness of the wiping tape itself. Furthermore, another objective is to provide a heat-cutting apparatus suitable for manufacturing such a wiping tape.

[0018] The object of the present invention is a wiping cloth made of a fibrous structure using ultrafine polyamide fibers, wherein the single filament fineness of the ultrafine polyamide fibers is 0.7 dtex or less, the content of ultrafine polyamide fibers in the entire wiping cloth is 40% by mass or more, and the average number of airborne particles with a diameter of 0.1 μm or more is 10 particles / cm². ２ This is achieved by the following wiping cloth.

[0019] Furthermore, it is preferable that the ultrafine polyamide fibers are polyamide fibers obtained by dissolving an alkali-soluble polyester resin of a segmented composite fiber consisting of a polyamide component and an alkali-soluble polyester component, which substantially does not contain a matting agent, and that the cross-sectional shape of the polyamide fibers is an irregular cross-sectional shape.

[0020] Furthermore, it is preferable that the fibrous structure is a woven fabric in which at least the ultrafine polyamide fibers are used as weft threads.

[0021] Furthermore, the object of the present invention is achieved by a method for manufacturing a wiping cloth, which comprises the steps of weaving a fabric using a split-type composite fiber consisting of a polyamide component and an alkali-soluble polyester component, which is substantially free of a matting agent, at least as the weft, and dissolving the alkali-soluble polyester resin by immersing the obtained fabric in an alkaline solution.

[0022] Furthermore, in order to solve the above problems, the inventors focused on devising a method for melt-cutting the fabric (processed roll) for wiping tape when manufacturing wiping tape, and thus obtained the present invention. Specifically, the present invention firstly determines that the number of liquid particles of 0.2 μm or larger when immersed in pure water for 12 hours under a Class 100 environment is 5 particles / ml / cm². ２ The following concerns a wiping tape. Furthermore, it is a first wiping tape intended for magnetic recording disks.

[0023] Furthermore, the present invention relates to a method for manufacturing a wiping tape, characterized by heat-cutting the fabric for the wiping tape in a clean room, and immediately after heat-cutting, using a suction nozzle to suction the smoke generated by the heat-cutting.

[0024] Furthermore, the manufacturing method preferably includes a first step of transporting the washed fabric for the wiping tape, a second step of heat-cutting the transported fabric with a first cutting blade, and a third step of transporting the fabric while sucking up the smoke generated by the heat-cutting with a first suction nozzle immediately after the heat-cutting. Furthermore, in the manufacturing method, it is preferable that the first to third steps be performed in a clean room. Furthermore, in the manufacturing method, it is preferable that the distance between the first cutting blade and the first suction nozzle is 30 mm or more and 100 mm or less. Furthermore, in the manufacturing method, it is preferable that the suction pressure from the first suction nozzle is 0.1 kPa or more and 0.5 kPa or less.

[0025] Furthermore, the present invention relates to a heat-cutting device for wiping tape, comprising a first conveying unit for conveying fabric for wiping tape, a first heat-cutting unit for heat-cutting the fabric conveyed from the first conveying unit, and a second conveying unit for conveying the heat-cut fabric to the next process, wherein a first suction nozzle for sucking up particles and smoke from the surface of the fabric is provided between the first heat-cutting unit and the second conveying unit. Preferably, the heat-cutting device comprises a second heat-cutting unit after the second conveying unit, and a second suction nozzle for sucking up particles and smoke from the surface of the fabric is provided after the second heat-cutting unit.

[0026] Since the wiping cloth of the present invention has an extremely small amount of ultrafine particles, there is no generation of contamination. Further, by containing a specific amount or more of polyamide fibers, an increase in particles due to friction during wiping is suppressed. Also, by using ultra-fine polyamide fibers with a single filament fineness of 0.7 dtex or less, the wiping property is high and there is little residue after wiping, making it a wiping cloth suitable for media cleaning applications. Further, a split-type composite fiber composed of a polyamide resin and an alkali-soluble polyester resin and substantially free of a matting agent is used at least for the weft yarn to form a fabric, and then the alkali-soluble polyester resin is dissolved with an alkaline solution, so that oligomers and the like contained in polyamide and polyester that are not alkali-soluble are removed, and thus the number of particles due to self-dust generation in the wiping cloth can be reduced.

[0027] Further, according to the present invention, a wiping tape with improved cleanliness of the tape itself can be obtained.

[0028] Explanatory drawing showing an example of the cross-sectional shape of the ultra-fine fiber used in the present invention. Explanatory drawing showing another example of the cross-sectional shape of the ultra-fine fiber used in the present invention. Explanatory drawing showing another example of the cross-sectional shape of the ultra-fine fiber used in the present invention.

[0029] Hereinafter, the present invention will be described in detail.

[0030] The wiping cloth of the present invention is a fiber structure using ultra-fine fibers of polyamide.

[0031] The ultra-fine fibers constituting the wiping cloth need to be polyamide fibers with a single filament fineness of 0.7 dtex or less. Also, the single filament fineness is preferably 0.6 dtex or less. If the single filament fineness is 0.7 dtex or less, the obtained wiping cloth will be more excellent in flexibility and denseness and suitable for polishing performance and cleaning performance.

[0032] The content of the ultra-fine fibers of polyamide in the entire wiping cloth of the present invention needs to be 40% by mass or more. If the content is 40% by mass or more, the generation of particles due to friction during media wiping is small.

[0033] The wiping cloth of the present invention preferably contains 30% by mass or more of polyester. By using polyester fiber or composite fiber containing polyester as the warp, the morphological stability is improved, and it is easy to maintain the width of the tape when used as a wiping tape.

[0034] The wiping cloth of the present invention has an average value of the number of airborne particles with a diameter of 0.1 μm or more of 10 or less. If it is 10 pieces / cm ２ or less, it is difficult to damage the medium.

[0035] The wiping cloth of the present invention has excellent wiping performance in the use of precision equipment in a clean room, such as being used in the manufacturing process of hard disks, etc. The form of the wiping cloth may be used as a cut-to-size and shape such as a string shape, a tape shape, a square, etc.

[0036] The ultra-fine polyamide fiber in the present invention is preferably a fiber formed by using a segmented composite fiber composed of a polyamide component and an alkali-soluble polyester component and splitting the segmented composite fiber by alkali treatment.

[0037] The present invention also relates to a wiping tape suitable for wiping magnetic disks, etc. in a clean room.

[0038] The wiping tape of the present invention is a wiping tape having a number of in-liquid particles of 0.2 μm or more of 5 pieces / ml / cm when immersed in pure water for 12 hours in an environment of class 100. ２ By setting the number of particles within such a range, self-dust generation is reduced, the wiping performance on the medium is improved, and the residual particles during wiping of the medium are reduced. The number of in-liquid particles of 0.2 μm or more is preferably 4 pieces / ml / cm ２ or less, and more preferably 3.5 pieces / ml / cm ２ or less.

[0039] Suitable materials for the wiping tape of the present invention include fibrous structures made of ultrafine fibers such as polyester, polyamide, and polyolefin, and may include, for example, a fibrous structure containing ultrafine polyamide fibers.

[0040] The ultrafine fibers mentioned above may be split composite fibers made of polyester and polyamide components, and the fibers may be formed by splitting the split composite fibers with a swelling agent such as benzyl alcohol.

[0041] Alternatively, the ultrafine polyamide fiber may be a split-type composite fiber consisting of a polyamide component and an alkali-soluble polyester component, and the fiber may be formed by splitting the split-type composite fiber through alkali treatment.

[0042] The ultrafine fibers constituting the wiping tape preferably have a single-fiber fineness of 0.7 dtex or less. Furthermore, it is preferable that the single-fiber fineness is 0.6 dtex or less. If the single-fiber fineness is 0.7 dtex or less, the resulting wiping tape will have superior flexibility and density, making it suitable for polishing and cleaning performance.

[0043] Polyethylene terephthalate and polybutylene terephthalate are preferred examples of the polyester components mentioned above.

[0044] Examples of the polyamide components mentioned above include aliphatic polyamides such as polyamide 6, polyamide 6,6, and polyamide 4,6.

[0045] Furthermore, a polyamide resin composition comprising an aromatic polyamide and an aliphatic polyamide may be used as the polyamide component. Examples of aromatic polyamides include polyamides having aliphatic dicarboxylic acids and aromatic diamines as the main structural units.

[0046] The above polyamide resin composition exhibits high shrinkage performance, resulting in good splitting properties upon treatment with a swelling agent, alkaline dissolution, or hot water treatment. The resulting fibrous structure is dense and bulky, providing wiping performance suitable for polishing and cleaning hard disks and other devices.

[0047] Specifically, examples include a resin obtained from metaxylylenediamine and adipic acid as the aromatic polyamide (polyamide MXD6), and a resin obtained from ε-caprolactam as the aliphatic polyamide (polyamide 6). The preferred mass mixing ratio of polyamide MXD6 and polyamide 6 is 35:65 to 70:30.

[0048] On the other hand, the above-mentioned alkali-soluble polyester components include polyalkylene glycols, isophthalic acid components containing metal sulfonate groups, and polyester components copolymerized with adipic acid.

[0049] In particular, it is preferable that the polyester has ethylene terephthalate as its main repeating unit, contains 2.0 to 3.0 mol% of a metal sulfonate group-containing isophthalic acid component in the acid component, and contains 9 to 13% by mass of polyalkylene glycol with an average molecular weight of 1,000 to 10,000 in the polymer. Furthermore, it is preferable that the polyester component has a mol% of DEG contained in it of 4.7 to 5.7 mol% in the glycol component, and the ratio of the maximum intrinsic viscosity [η]max to the minimum intrinsic viscosity [η]min is 1.0 ≤ [η]max / [η]min ≤ 1.02.

[0050] The metal sulfonate group-containing isophthalic acid component used in the present invention is either dimethyl 5-metal sulfisoisophthalate (hereinafter referred to as SIPM) or a compound obtained by esterifying a methyl group with ethylene glycol (hereinafter referred to as SIPE). Since adding a large amount of SIPM to the slurry tank can worsen the properties of the slurry, it is preferable to use SIPE. Sodium, potassium, lithium, etc., can be used as the metal in SIPM or SIPE, but sodium is the most preferred.

[0051] The copolymerization ratio of the SIPEs is preferably 2.0 to 3.0 mol% in the acid component of the polymer. If the copolymerization ratio of the SIPEs is less than this, it tends to be difficult to obtain sufficient alkali solubility. On the other hand, if the copolymerization ratio is more than this, thickening and gelation due to the charge of the SIPEs occur in the melt spinning process, and the operability tends to be significantly reduced. The copolymerization ratio of the SIPEs is preferably 2.0 to 3.0 mol% in the acid component of the polymer in terms of easily maintaining sufficient alkali solubility and spinnability well.

[0052] In addition, the polyalkylene glycol is represented by the general formula HO(C ｎ H ２ｎ O) ｍ H (where ｎ , ｍ is a positive integer), and polyethylene glycol with n = 2 (hereinafter sometimes referred to as PEG) is general-purpose and most preferred. The molecular weight of the polyalkylene glycol used in the present invention is preferably 1000 to 10000. If the molecular weight is less than 1000, the hydrolysis reaction of the modified polyester easily occurs during melt spinning, the heat resistance of the polyester is insufficient, and there is a tendency for the polyester pellets to fuse together and for white powder to occur in the false twisting process. Further, if the molecular weight exceeds 10000, the polymerization reactivity deteriorates, and it is difficult for the polyalkylene glycol to be copolymerized into the molecular chain of the polyester, so the oxidation resistance of the polyester tends to be inferior. The molecular weight of the polyalkylene glycol used in the present invention is preferably 1000 to 10000 from the viewpoint of being suitably used for the spinning and false twisting processes.

[0053] The copolymerization amount of the polyalkylene glycol may be 9 to 13% by mass based on the polymer. If the copolymerization amount is less than 9% by mass, the alkali water dissolution performance tends not to be sufficiently obtained. On the other hand, if it exceeds 13% by mass, the heat resistance and oxidation resistance of the polymer tend to deteriorate. The copolymerization amount of the polyalkylene glycol is preferably 9% by mass or more and 13% by mass or less based on the polymer in terms of maintaining good alkali water solubility, heat resistance, and oxidation resistance.

[0054] The intrinsic viscosity of the above polyester is such that the ratio of the maximum value [η]max to the minimum value [η]min is 1.0 ≤ [η]max / [η]min ≤ 1.02. If [η]max / [η]min falls outside this range, yarn breakage during melt spinning occurs frequently, spinning filterability is poor, and spinneret life is shortened, resulting in poor operability. From the standpoint of operability during spinning and ease of handling in subsequent processes, it is preferable that the ratio of the maximum value [η]max to the minimum value [η]min of the above polyester is 1.0 ≤ [η]max / [η]min ≤ 1.02.

[0055] Furthermore, the alkali-soluble polyester component used in the present invention preferably contains 4.7 to 5.7 mol% of diethylene glycol (DEG) in the glycol component. This DEG is produced by a side reaction during polymerization. If the DEG content is less than 4.7 mol%, the alkali water solubility is poor. If it exceeds 5.7 mol%, the heat resistance and oxidation resistance of the polymer are poor, and the operability during melt spinning becomes significantly worse.

[0056] Furthermore, it is preferable that the above-mentioned polyester component, polyamide component, and alkali-soluble polyester component do not contain matting agents. Matting agents are inorganic or organic particles such as titanium dioxide, silicon dioxide, and aluminum oxide, which are usually added to suppress the gloss of the yarn or to improve spinning performance. In this context, "not containing matting agents" means that matting agents such as titanium dioxide, which are usually added to suppress the gloss of the yarn or to improve spinning performance, are not actively added. This is because if matting agents are included, they may come off due to physical force during wiping, causing scratches on magnetic recording media, etc. Note that trace amounts may be present due to contamination during the manufacturing and processing process. Even in such cases, if the analytical value using a general ash content measurement method is less than 50 ppm in the polymer, the surface will not be scratched during hard disk polishing or cleaning.

[0057] When the above-mentioned components are combined into a split composite fiber, the polyester component dissolves completely and the fiber is split when subjected to alkaline dissolution processing. Furthermore, heating during this alkaline dissolution process, or by a separate heat treatment, causes the polyamide component to shrink, resulting in a high-density, bulky wiping cloth or wiping tape.

[0058] Preferably, the cross-sectional shape of the above-mentioned segmented composite fiber is such that the polyester component and the polyamide component, or the polyamide component and the alkali-soluble polyester component, are joined along the longitudinal direction of the single fiber in a cross-section such that one component does not completely encompass the other component. Specifically, examples include radial segmented composite fibers joined in a radial and complementary radial shape as shown in Figures 1 and 2, and central circular segmented composite fibers as shown in Figure 3.

[0059] In the case of a split-type composite fiber of a polyester component and a polyamide component, in Figures 1 and 2, 1 and 2 represent the polyester component or the polyamide component. That is, if one is the polyester component, the other is the polyamide component. In the present invention, it is preferable to use a split-type composite fiber in which 1 is the polyamide component and 2 is the polyester component.

[0060] In the case of a split-type composite fiber comprising a polyamide component and an alkali-soluble polyester component, in the figure, 1 and 2 represent the polyamide component or the alkali-soluble polyester component, respectively. That is, if one is the polyamide component, the other is the alkali-soluble polyester component. In the present invention, using a split-type composite fiber in which 1 is the alkali-soluble polyester component and 2 is the polyamide component is preferable in that it allows the abrasion resistance of the polyamide to be more fully exhibited.

[0061] As described above, the ultrafine fibers in the present invention are preferable in terms of wiping performance during media cleaning if the fiber cross-sectional shape is an irregular cross-sectional shape.

[0062] The total fineness of the above-mentioned split composite fibers can be appropriately determined within the spinnable range. From the viewpoint of fiber shrinkage performance, which affects the wiping performance of the wiping cloth or wiping tape, a total fineness of 30 to 300 dtex is preferable. More preferably, it is 40 to 200 dtex, and particularly preferably 50 to 150 dtex.

[0063] Fiber structures using the above-mentioned segmented composite fibers include yarns, woven fabrics, knitted fabrics, and nonwoven fabrics, with woven fabrics being preferred among them. When used as a wiping tape, woven fabrics are less prone to warp stretching. If the tape stretches warp during use, it tends not to be wound up properly. Also, when the tape is made narrow, there is a risk of problems such as residue remaining on the wiping surface when it comes into contact with the wiping surface.

[0064] If the above fiber structure is a woven fabric, examples of weave structures include plain weave, satin weave, and twill weave. For wiping cloths, plain weave, satin weave, and twill weave are preferred, for example. Satin weave is preferred because it allows for a denser fabric.

[0065] Furthermore, if the fibrous structure is a woven fabric, the segmented composite fiber can be used in the weft, warp, or both.

[0066] In this case, it is preferable to use regular polyester fibers (polyethylene terephthalate fibers) or polyamide fibers for the warp threads.

[0067] In particular, when using the wiping cloth of the present invention in a tape-like shape, it is preferable that the weft yarn be made of ultrafine polyamide fibers. Using ultrafine polyamide fibers as the weft yarn in the wiping direction (perpendicular to the direction of travel) results in good wiping performance. Therefore, it is preferable to use the above-mentioned segmented composite fibers as the weft yarn during weaving.

[0068] In this case, it is preferable to use regular polyester fibers (polyethylene terephthalate fibers) for the warp threads.

[0069] When used in woven fabrics, the preferred finishing cover factor (K), calculated using the following formula, is preferably 1000 or more for warp and 800 or more for weft in the case of plain weave, and preferably 1200 or more for warp, more preferably 1500 or more for warp and 800 or more for weft, and more preferably 1000 or more for satin weave.

[0070]

[0071] When the fiber structure of the present invention is a knitted fabric, it may be warp knitted or weft knitted. Specifically, a weft knitted structure is preferred, and when used as a wiping cloth, for example, an interlock structure is preferred. When the fiber structure of the present invention, which is a knitted fabric, is used as a wiping cloth in a cleanroom, for example, it is preferable to have a wale count of 70 to 100 threads / inch and a course count of 70 to 100 threads / inch. In the case of tricot, it is preferable to use about 28G. Furthermore, even if the above-mentioned split fibers are used for all of the front yarn, back yarn, and middle yarn, or if only a part of them are split fibers, it is more preferable to use them for at least the front and back.

[0072] The wiping cloth of the present invention is preferably obtained by manufacturing a fibrous structure from the above-mentioned segmented composite fibers by an appropriate conventional method, then splitting the segmented composite fibers by alkaline dissolution treatment, and further performing heat treatment or the like as necessary.

[0073] The wiping tape of the present invention is preferably obtained by manufacturing a fibrous structure from the above-mentioned segmented composite fibers by an appropriate conventional method, then splitting the segmented composite fibers by applying a swelling agent or an alkaline dissolution treatment, and further performing heat treatment or the like as necessary.

[0074] Alkaline dissolution treatment removes oligomers and other substances contained in polyamides and polyesters using an alkaline aqueous solution. This is preferable because it reduces the number of self-generated particles in the wiping cloth or wiping tape.

[0075] The alkaline dissolution treatment is a method in which the split composite fibers of the present invention are immersed in a heated alkaline solution, dissolving the alkali-soluble polyester component and simultaneously shrinking the polyamide component to cause splitting. In this process, self-generated fine particles and low molecular weight substances mainly derived from oligomers contained in the alkali-soluble polyester component are dissolved and removed by the alkaline solution, thereby reducing the number of self-generated particles in the product.

[0076] The conditions for the alkaline dissolution treatment can be those generally used in the weight reduction processing of polyester fiber structures. For example, a method using a 0.5 to 5% by mass aqueous solution of sodium hydroxide can be used. More preferably, it is 1 to 3% by mass, and particularly preferably, 1 to 2% by mass. The treatment temperature is preferably 85 to 100°C, and more preferably 90 to 98°C.

[0077] Furthermore, it is preferable to heat-treat the fiber structure obtained by the above-mentioned alkali dissolution treatment. Such heat treatment can shrink the fibers, increase the density of the fabric, increase the surface area of ​​the fabric, and improve its wiping properties. The heat treatment conditions can be, for example, 120 to 150°C for 0.5 to 1 hour under moist heat conditions, or 150 to 190°C for 30 seconds to 1 minute under dry heat conditions. The above heat treatment may be performed simultaneously with the dyeing treatment. That is, the fibers may be shrunk by the heat treatment for dyeing.

[0078] In the method for manufacturing a wiping cloth or wiping tape of the present invention, it is preferable to obtain the final fiber structure by performing the above-described processes on the raw fabric obtained through processes such as weaving and knitting, thereby shrinking the woven fabric by 10 to 30% in the width direction and the knitted fabric by 40 to 60% in the width direction. Obtaining such a shrinkage rate is preferable in that it provides excellent wiping properties. The above shrinkage rate is determined by the width of the raw fabric W ０ Let W be the width after shrinkage. 100 × {(W ０ -W) / (W ０ It can be calculated using the formula )}(%).

[0079] Then, when used for polishing or cleaning precision electronic equipment such as hard disks in a cleanroom, the obtained fabric is washed with pure water in the cleanroom and dried, and cut to the desired size as needed. After that, if necessary, it is washed with pure water in the cleanroom and dried to obtain a wiping cloth. The obtained wiping cloth can be sealed in a resin film pack. When using this sealed pack in the manufacturing process of hard disks, etc., the pack can be opened and the wiping cloth can be used.

[0080] The wiping cloth of the present invention, obtained as described above, contains a large amount of ultrafine polyamide fibers, and has an average number of airborne particles with a diameter of 0.1 μm or more of 10 particles / cm². ２ As described below, it does not cause contamination and has excellent wiping properties.

[0081] Furthermore, when used for polishing or cleaning precision electronic equipment such as hard disks in a cleanroom, the resulting fibrous structure, such as a woven fabric, is then washed with pure water in the cleanroom and dried, and cut to the desired width as needed. After that, if necessary, it is washed with ultrapure water in the cleanroom and dried to obtain a processed roll (fabric for wiping tape). Then, by melt-cutting or other methods, the desired wiping tape can be obtained. The obtained wiping tape can be sealed in a resin film pack. This sealed pack can then be opened and used as wiping tape when used in the manufacturing process of hard disks, etc.

[0082] In the present invention, the processed fabric obtained by the above methods is melt-cut into a tape shape using a slitting method so as not to generate dust from the wiping tape itself. When melt-cutting the processed fabric using a slitting method, heat cutting is the mainstream method, but when cutting with heat, a certain amount of smoke is generated, which may cause contamination of the wiping tape after cutting. For this reason, the manufacturing method of the wiping tape of the present invention incorporates measures when heat cutting to reduce contamination of the wiping tape after cutting and self-dust generation.

[0083] In this invention, it is preferable to perform heat cutting in a cleanroom. It is also preferable to provide an exhaust hood above the heat cutting device. This reduces the amount of smoke adhering to the wiping tape, even when melt cutting is performed using a slit method.

[0084] Furthermore, when using a heat-cutting device, it is preferable to install a suction nozzle capable of sucking up smoke, etc., near the cutting blade, for example, at a distance of 30 mm to 100 mm, after cutting. This allows smoke, etc., to be sucked up immediately after heat cutting, reducing the adhesion of smoke and other dust to the wiping tape, and also allows the molten cut edge of the wiping tape, even if it is narrow, to be kept clean.

[0085] The melting and cutting speed during heat cutting is preferably between 5 m / min and 200 m / min.

[0086] The thickness of the fabric of the wiping tape of the present invention can be appropriately set according to the desired application. In the case of a wiping tape for magnetic disks, the width of the tape may be, for example, 3 mm to 100 mm, 5 mm to 50 mm, and preferably 5 mm to 30 mm.

[0087] When the wiping tape of the present invention is melt-cut by heat cutting, it can be cut at a cutting temperature of, for example, 600°C or higher (630°C). The preferred cutting temperature varies depending on the material and cutting speed, but in the case of polyester and polyamide, a temperature and speed that does not cause yellowing is preferred, and the upper limit is preferably around 700°C.

[0088] Furthermore, in this invention, when cutting the fabric, it is preferable to heat-cut the fabric for the wiping tape in a clean room, and immediately after heat-cutting, it is preferable to suction the smoke generated by the heat-cutting using a suction nozzle. One suction nozzle may be provided, or two or more may be provided at intervals. In this case, it is preferable to ensure that the entire surface of the fabric is suctioned. This makes it easier to obtain a wiping tape with no fraying of threads at the cut edges, even when cutting to a narrow width, and with a reduced number of particles coming from the tape itself, resulting in a wiping tape with less dust generation during manufacturing and use, and a high degree of cleanliness with less contamination.

[0089] Furthermore, the present invention may also be a method for manufacturing a wiping tape that includes a first step of washing a fibrous structure (raw fabric) that has been woven or knitted as described above with pure water and transporting the washed wiping tape fabric (processed roll), a second step of heat-cutting the transported wiping tape fabric with a first cutting knife, and a third step of transporting the wiping tape fabric immediately after heat-cutting while sucking up the smoke generated by the heat-cutting with a first suction nozzle.

[0090] By using a suction nozzle to vacuum the entire surface of the fabric immediately after heat cutting, it is easier to obtain a wiping tape that does not fray at the cut edges and has a reduced number of particles coming from the tape itself. This results in a wiping tape with less dust generation during manufacturing and use, and a high degree of cleanliness with less contamination. To further improve the cleanliness of the wiping tape, the entire surface of the fabric may be vacuumed using another suction nozzle.

[0091] In the above case, the distance between the first cutting blade and the first suction nozzle is preferably 30 mm or more and 100 mm or less, and the suction pressure from the first suction nozzle is preferably 0.1 kPa or more and 0.5 kPa or less in order to maintain the cleanliness of the wiping tape and obtain excellent wiping performance.

[0092] When a second suction nozzle is provided, the distance between the first and second suction nozzles is preferably 30 mm to 100 mm, and the suction pressure from the second suction nozzle is preferably 0.1 kPa to 0.5 kPa. This makes it easier to obtain a wiping tape without fraying at the cut edges and with a reduced number of particles coming from the tape itself, and is also preferable for maintaining the cleanliness of the wiping tape and obtaining excellent wiping performance. Furthermore, from the viewpoint of obtaining excellent cleanliness, it is even more preferable to perform the heat cutting and suction in a cleanroom.

[0093] Furthermore, in order to manufacture the wiping tape as described above, a heat cutting device may be used that includes a first conveying unit for conveying the fabric for the wiping tape, a first heat cutting unit for heat cutting the fabric conveyed from the first conveying unit, and a second conveying unit for conveying the heat-cut fabric to the next process, with a first suction nozzle between the first heat cutting unit and the second conveying unit for sucking up particles from the surface of the fabric. Alternatively, the heat cutting device may include a second heat cutting unit after the second conveying unit, and a second suction nozzle after the second heat cutting unit for sucking up particles and smoke from the surface of the fabric. This can improve the heat cutting and conveying efficiency.

[0094] Although a suction nozzle was used in the above example, a suction device that is not nozzle-shaped may also be used.

[0095] Using the manufacturing method described above, the number of particles larger than 0.2 μm in the liquid after immersion in pure water for 12 hours under a Class 100 environment is 5 particles / ml / cm². ２ The following wiping tape can be obtained.

[0096] The breaking strength of the fabric constituting the wiping tape is preferably 800 N or more, and more preferably 1000 N or more.

[0097] The break elongation of the fabric constituting the wiping tape is preferably 50% or less, and more preferably 35% or less. Within this range, the tape does not stretch excessively during use, making it easy to handle even with a small tape width, and reducing streaks on the wiping surface, resulting in good wiping performance.

[0098] Furthermore, the wiping tape in this invention may contain a large amount of ultrafine polyamide fibers, and the average number of airborne particles with a diameter of 0.1 μm or more may be 10 or less. This allows for even better results, resulting in no contamination and superior wiping properties. Here, the number of airborne particles with a diameter of 0.1 μm or more is the value measured below. A 1 cm wide tape-shaped wiping cloth is cut to a length of 20 cm to serve as a sample. In a Class 100 cleanroom, the sample is placed on the measuring stage of a surface particle detector (QIII Ultra®, manufactured by Pentagon Technologies, Inc.), with both ends of the sample fixed with a jig, and the total number of particles on the sample surface between 0.1 μm and 5 μm is measured. Three different locations on the same sample are measured, and the average value is taken as the number of airborne particles with a diameter of 0.1 μm or more (the unit of total particles is particles / cm). ２ ).

[0099] The wiping tape of the present invention may contain 40% by mass or more of ultrafine polyamide fibers overall, as this makes it easier to reduce particles caused by friction during media wiping.

[0100] The wiping tape of the present invention may contain 30% by mass or more of polyester fibers. By using polyester fibers or composite fibers containing polyester in the warp threads, the shape stability is improved, making it easier to maintain the tape width when used as a wiping tape.

[0101] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to the examples described below.

[0102] Furthermore, the evaluation methods are as follows:

[0103] <Intrinsic Viscosity of Polyester> The intrinsic viscosity [η] was measured by a conventional method using an automatic viscometer in a mixed solvent of phenol / tetrachloroethane = 6 / 4 (mass ratio) at 20°C.

[0104] <Relative viscosity of polyamide> The relative viscosity ηrel was measured by a conventional method using an Oswald viscometer at 20°C in a sulfuric acid solvent.

[0105] <Measurement of Airborne Particle Count> A 1 cm wide tape-shaped wiping cloth was cut to a length of 20 cm and used as a sample. In a Class 100 cleanroom, the sample was placed on the measuring stage of a surface particle detector (Pentagon Technologies QIII Ultra® registered trademark) with both ends of the sample fixed with a jig, and the total number of particles between 0.1 μm and 5 μm in diameter on the sample surface was measured. Three different locations on the same sample were measured, and the average value was taken as the number of airborne particles with a diameter of 0.1 μm or larger. The unit of the total number of particles is particles / cm. ２ That is the case.

[0106] <Measurement of particle count in liquid> A sample of approximately 1.25 m was used. ２ Prepare a piece of tape cut to size (10 m for a 12.5 mm width). Immerse the cut tape in 400 ml of ultrapure water and leave it standing in a running clean bench for at least 12 hours. Remove the immersed sample with cleaned tweezers, let it stand for at least 5 minutes, and then measure the number of particles in the liquid using a RION particle counter (KS-28b). The resulting number of particles was divided by the volume of ultrapure water and the surface area of ​​the fabric to calculate the number of particles per unit area (particles / ml / cm²). ２ ). Furthermore, all work related to the measurements was carried out in a Class 100 cleanroom.

[0107] <Media wiping evaluation> A disc-shaped glass media was attached to a device capable of rotating at 1000-3000 rpm, and a wiping cloth of 150 g / cm² was applied to each. ２The media was rotated for one minute while being pressed down with pressure at rotation speeds of 1000 rpm and 3000 rpm. The number of bright spots, believed to be dust, transferred onto the media was measured using a VisionScytech Micro-MAX. All of these operations were performed in a Class 100 cleanroom.

[0108] (Example 1) As the polyamide component, polyamide 6 (manufactured by Ube Industries, Ltd.) with a relative viscosity of 2.7 and substantially free of a matting agent (titanium dioxide) was used. On the other hand, as the alkali-soluble polyester component, copolymer polyethylene terephthalate (mainly composed of terephthalic acid and ethylene glycol, containing 2.3 mol% SIPE in the acid component, 10% by mass of polyethylene glycol with an average molecular weight of 8000, and 5.5 mol% DEG) with an intrinsic viscosity of 0.77 and substantially free of a matting agent was used. With a volume ratio of radially branched segment 1 to segment 2 that replenishes the radial portion of 3:7, melt-compound spinning was performed at a spinning temperature of 295°C and a spinning speed of 1050 m / min such that the alkali-soluble polyester component constituted the radially branched segment 1 and the polyamide component constituted the segment 2 that replenishes the radial portion of 1, obtaining an undrawn yarn with a fiber cross-sectional shape similar to that shown in Figure 2. The obtained undrawn yarn was then drawn using a roller heater at 85°C, a plate heater at 150°C, and a draw ratio of 3.0 to obtain a split-type composite fiber of 84 dtex / 25f. This drawn yarn was used as the weft, and regular polyester fibers (intrinsic viscosity 0.61, 84 dtex / 36f) spun using polyethylene terephthalate without a matting agent were used as the warp to obtain a back satin fabric. The obtained fabric was immersed in a 2% by mass sodium hydroxide aqueous solution (temperature 95°C) for 30 minutes to perform an alkaline dissolution treatment. After the alkaline dissolution treatment, the fabric was divided and shrunk by washing with pure water to obtain a wiping cloth. The polyamide fiber content in the weft of the obtained wiping cloth was 60 dtex / 200f, and the single yarn fineness was 0.29 dtex. The polyamide fiber content in the entire obtained wiping cloth was 40% by mass. The obtained wiping cloth was heat-cut so that the weft direction became the width direction to create 1 cm wide tape-shaped wiping cloth, which was then evaluated. The results are shown in Table 1.

[0109] (Example 2) A wiping cloth was obtained in the same manner as in Example 1, except that a segmented composite fiber (84 dtex / 28f) with the same fiber cross-sectional shape as in Figure 1 was used as the weft, with a volume ratio of 3:7 between the radially branching segment 1 and the segment 2 that supplements the radial portion, where the alkali-soluble polyester component constitutes the radially branching segment 1 and the polyamide component constitutes the segment 2 that supplements the radial portion. The polyamide fiber content in the weft of the obtained wiping cloth was 60 dtex / 112f, and the single filament fineness was 0.53 dtex. The polyamide fiber content in the entire obtained wiping cloth was 40% by mass. The obtained wiping cloth was heat-cut so that the weft direction was the width direction to obtain 1 cm wide tape-shaped wiping cloth, which was then evaluated. The results are shown in Table 1.

[0110] (Example 3) A wiping cloth was obtained in the same manner as in Example 1, except that a regular polyester fiber (intrinsic viscosity 0.61, 33 dtex / 12f) that was substantially free of a matting agent was used as the warp thread. The polyamide fiber content in the entire wiping cloth obtained was 45% by mass. The obtained wiping cloth was heat-cut so that the weft direction was the width direction to obtain 1 cm wide tape-shaped wiping cloths, which were then evaluated. The results are shown in Table 1.

[0111] (Example 4) A wiping cloth was obtained in the same manner as in Example 1, except that a core-sheath type composite fiber (56dtex / 24f) was used as the warp thread, in which the core was made of regular polyester (intrinsic viscosity 0.61) that was substantially free of a matting agent and the sheath was made of polyamide 6 (manufactured by Ube Industries, Ltd.) with a relative viscosity of 2.7 that was substantially free of a matting agent. The polyamide content in the entire obtained wiping cloth was 50% by mass. The obtained wiping cloth was heat-cut so that the weft direction was the width direction to make 1 cm wide tape-shaped wiping cloths, which were then evaluated. The results are shown in Table 1.

[0112] (Comparative Example 1) A fabric was obtained in the same manner as in Example 1, except that the volume ratio of radially branching segment 1 to segment 2 supplementing the radial portion was 3:7, and the radially branching segment 1 was composed of polyamide 6 (manufactured by Ube Industries, Ltd.) with a relative viscosity of 2.7 that was substantially free of a matting agent (titanium dioxide), and the segment 2 supplementing the radial portion was composed of regular polyester with an intrinsic viscosity of 0.61 that was substantially free of a matting agent, and a split composite fiber (56 dtex / 28f) with the same fiber cross-sectional shape as in Figure 1 was used as the weft. The obtained fabric was subjected to a splitting treatment by immersing it in a 2 mass% sodium hydroxide aqueous solution (temperature 95°C) for 20 minutes. After the splitting treatment, a shrinkage treatment was performed by washing with pure water to obtain a wiping cloth. The single filament fineness of the polyamide fibers in the weft of the obtained wiping cloth was 0.60 dtex. The polyamide fiber content in the entire obtained wiping cloth was 15 mass%. The obtained wiping cloth was heat-cut so that the weft direction became the width direction to create 1 cm wide tape-shaped wiping cloth, which was then evaluated. The results are shown in Table 1.

[0113] (Comparative Example 2) A fabric was obtained in the same manner as in Example 1, except that the volume ratio of radially branching segment 1 to segment 2 supplementing the radial portion was 3:7, regular polyester with an intrinsic viscosity of 0.61 that is substantially free of a matting agent constituted the radially branching segment 1, and polyamide 6 (manufactured by Ube Industries, Ltd.) with a relative viscosity of 2.7 that is substantially free of a matting agent constituted the segment 2 that supplements the radial portion, and a split composite fiber (56 dtex / 28f) with the same fiber cross-sectional shape as in Figure 1 was used as the weft. The obtained fabric was subjected to a splitting treatment by immersing it in a 2 mass% sodium hydroxide aqueous solution (temperature 95°C) for 20 minutes. After the splitting treatment, a shrinkage treatment was performed by washing with pure water to obtain a wiping cloth. The single filament fineness of the polyamide fibers in the weft of the obtained wiping cloth was 0.35 dtex. The polyamide fiber content in the entire obtained wiping cloth was 35 mass%. The obtained wiping cloth was heat-cut so that the weft direction became the width direction to create 1 cm wide tape-shaped wiping cloth, which was then evaluated. The results are shown in Table 1.

[0114] (Comparative Example 3) A fabric was obtained in the same manner as in Example 1, except that the volume ratio of the radially branching segment 1 to the segment 2 that supplements the radial portion was 3:7, the radially branching segment 1 was composed of polyamide 6 (manufactured by Ube Industries, Ltd.) with a relative viscosity of 2.7 that substantially does not contain a matting agent, and the segment 2 that supplements the radial portion was composed of regular polyester with an intrinsic viscosity of 0.61 that contains 0.3% by mass of a matting agent, and a split composite fiber (56 dtex / 28f) with the same fiber cross-sectional shape as in Figure 1 was used as the weft. The obtained fabric was subjected to a splitting treatment by immersing it in a 2% by mass sodium hydroxide aqueous solution (temperature 95°C) for 20 minutes. After the splitting treatment, a shrinkage treatment was performed by washing with pure water to obtain a wiping cloth. The single filament fineness of the polyamide fibers in the weft of the obtained wiping cloth was 0.60 dtex. The polyamide fiber content in the entire obtained wiping cloth was 15% by mass. The obtained wiping cloth was heat-cut so that the weft direction became the width direction to create 1 cm wide tape-shaped wiping cloth, which was then evaluated. The results are shown in Table 1.

[0115] (Comparative Example 4) A fabric was obtained in the same manner as in Example 1, except that the volume ratio of radially branching segment 1 to segment 2 that replenishes the radial portion was 3:7, and the radially branching segment 1 was composed of polyamide 6 (manufactured by Ube Industries, Ltd.) with a relative viscosity of 2.7 that is substantially free of a matting agent, and the segment 2 that replenishes the radial portion was composed of regular polyester with an intrinsic viscosity of 0.61 that is substantially free of a matting agent, and a split-type composite fiber (56dtex / 25f) with the same fiber cross-sectional shape as in Figure 2 was used as the weft, and a core-sheath type composite fiber (56dtex / 24f) in which the core is a regular polyester component (intrinsic viscosity of 0.61) that is substantially free of a matting agent and the sheath is polyamide 6 (manufactured by Ube Industries, Ltd.) with a relative viscosity of 2.7 that is substantially free of a matting agent was used as the warp. The obtained fabric was immersed in a 2% by mass aqueous sodium hydroxide solution (temperature 95°C) for 20 minutes to perform a splitting treatment. After the splitting treatment, it was subjected to a shrinkage treatment by washing with pure water to obtain a wiping cloth. The single filament fineness of the polyamide fibers in the weft of the obtained wiping cloth was 0.67 dtex. The total polyamide fiber content in the obtained wiping cloth was 15% by mass. The obtained wiping cloth was heat-cut so that the weft direction was the width direction to obtain 1 cm wide tape-shaped wiping cloth, which was then evaluated. The results are shown in Table 1.

[0116] (Comparative Example 5) A back satin fabric was obtained using a regular polyester fiber (33 dtex / 12f) with an intrinsic viscosity of 0.61 that was substantially free of matting agents as the warp thread, and a single yarn (44 dtex / 36f) of polyamide 6 (manufactured by Ube Industries, Ltd.) with a relative viscosity of 2.7 that was substantially free of matting agents as the weft thread. The fabric was subjected to shrinkage treatment by washing it with pure water to obtain a wiping cloth. The single yarn fineness of the polyamide fibers in the weft thread of the obtained wiping cloth was 1.22 dtex. The polyamide fiber content in the entire obtained wiping cloth was 40% by mass. The obtained wiping cloth was heat-cut so that the weft direction was the width direction to obtain 1 cm wide tape-shaped wiping cloths, which were then evaluated.

[0117]

[0118] The wiping cloths of Examples 1 to 4 had few airborne particles with a diameter of 0.1 μm or larger, and also produced few remaining particles after wiping, thus suppressing the increase in contamination during wiping. On the other hand, the wiping cloths of Comparative Examples 1 to 4 were polyester-based wiping tapes, and as the rotation speed of the media increased, the number of particles increased, resulting in insufficient wiping.

[0119] (Example 101) As the polyamide component, polyamide 6 (manufactured by Ube Industries, Ltd.) with a relative viscosity of 2.7 and substantially free of a matting agent (titanium dioxide) was used. On the other hand, as the alkali-soluble polyester component, copolymer polyethylene terephthalate (mainly composed of terephthalic acid and ethylene glycol, containing 2.3 mol% SIPE in the acid component, 10% by mass of polyethylene glycol with an average molecular weight of 8000, and 5.5 mol% DEG) with an intrinsic viscosity of 0.77 and substantially free of a matting agent was used. With a volume ratio of radially branched segment 1 to segment 2 that replenishes the radial portion of 3:7, melt-compound spinning was performed at a spinning temperature of 295°C and a spinning speed of 1050 m / min such that the alkali-soluble polyester component constituted the radially branched segment 1 and the polyamide component constituted the segment 2 that replenishes the radial portion of 1, obtaining an undrawn yarn with a fiber cross-sectional shape similar to that in Figure 2. The obtained undrawn yarn was then drawn using a roller heater at 85°C, a plate heater at 150°C, and a draw ratio of 3.0 to obtain a split-type composite fiber of 84 dtex / 25f. This drawn yarn was used as the weft, and regular polyester fibers (intrinsic viscosity 0.61, 84 dtex / 36f) spun using polyethylene terephthalate without a matting agent were used as the warp to obtain a back satin fabric. The obtained fabric was immersed in a 2% by mass sodium hydroxide aqueous solution (temperature 95°C) for 30 minutes to perform an alkaline dissolution treatment. After the alkaline dissolution treatment, the fabric was divided and shrunk by washing with pure water to obtain a processed roll. The polyamide fiber content in the weft of the obtained wiping cloth was 60 dtex / 200f, and the single yarn fineness was 0.29 dtex. The polyamide fiber content in the entire obtained wiping cloth was 40% by mass. The obtained processed roll was brought into a clean room. The processed fabric was heat-cut so that the weft direction was the width direction to create 1 cm wide Wipin tape, which was then evaluated. For the heat cutting, a heat cutting device was used that included a first conveying unit with an exhaust hood, a heat cutting unit with a first cutting blade, a first suction unit with a first suction nozzle, a second conveying unit, a second heat cutting unit with a second cutting blade, and a second suction unit with a second suction nozzle.Specifically, the processed material was transported to the first transport unit and then to the first heat-cutting device, where it was cut with the first cutting blade. After that, it was suctioned at a pressure of 0.14 kPa using the first suction nozzle at a distance of 8 cm from the cutting blade, then transported to the second transport unit, and then to the second heat-cutting device. After heat-cutting with the second cutting blade, it was suctioned at a pressure of 0.14 kPa using the second suction nozzle at a distance of 5 cm from the cutting blade to obtain a wiping tape. The number of liquid particles larger than 0.2 μm of the wiping tape after immersion in pure water for 12 hours in a Class 100 environment was 3.5 / ml / cm. ２ When we evaluated its wiping ability on media, we found that it had excellent wiping properties and did not generate any dust.

[0120] (Example 102) A wiping tape was obtained in the same manner as in Example 1, except that the cut width was changed to 2 cm. The number of liquid particles larger than 0.2 μm when the wiping tape was immersed in pure water for 12 hours under a Class 100 environment was 3.6 / ml / cm². ２ When we evaluated its wiping ability on media, we found that it had excellent wiping properties and did not generate any dust.

[0121] (Example 103) A wiping tape was obtained in the same manner as in Example 1, except that the suction pressure of the first suction nozzle was set to 0.4 kPa. The number of particles in the liquid was less than 5 / ml / cm2. When the wiping performance of the media was evaluated, it was found to have excellent wiping properties and did not generate dust on its own.

[0122] (Comparative Example 101) A wiping tape was obtained in the same manner as in Example 1, except that the distance from the first cutting blade to the first suction nozzle (suction start position) was changed to 2 cm.

[0123] (Comparative Example 102) A wiping tape was obtained in the same manner as in Example 1, except that the distance from the first cutting blade to the first suction nozzle (suction start position) was changed to 12 cm.

[0124] (Comparative Example 103) A wiping tape was obtained in the same manner as in Example 1, except that the suction pressure of the first suction nozzle was set to 0.05 kPa.

[0125] (Comparative Example 104) A wiping tape was obtained in the same manner as in Example 1, except that the suction pressure of the first suction nozzle was set to 0.7 kPa.

[0126] The wiping tapes of Examples 101 to 103 exhibited low self-dusting and high cleanliness. The wiping tape obtained in Comparative Example 101 had a small distance from the heat-cutting position to the suction start position of the suction nozzle, which affected the temperature of the cutting blade, resulting in an inability to form a clean cut surface. Self-dusting occurred during media use, and the wiping performance was inferior to that of the Examples. The wiping tapes obtained in Comparative Examples 102 and 103 had a particle count of 5 / ml / cm² in the liquid. ２ It exceeded the limit. Compared to the wiping tape of the example, the resulting wiping tape had inferior wiping properties and self-dusting properties. The wiping tape obtained in Comparative Example 104 had a large suction pressure (suction volume) from the suction nozzle, which affected the temperature of the cutting blade, and a clean cut melting surface could not be formed. Self-dusting occurred when using the media, and the wiping performance was inferior to that of the wiping tape of the example.

[0127] The wiping cloth and wiping tape of the present invention have excellent wiping properties, generate little self-dust, and have superior cleanliness, making them suitable for use with precision equipment such as magnetic recording media like hard disks.

[0128] 1. A segment that branches radially. 2. A segment that supplements the radial portion.

Claims

1. A wiping cloth made of a fibrous structure using ultrafine polyamide fibers, wherein the single filament fineness of the ultrafine polyamide fibers is 0.7 dtex or less, the content of ultrafine polyamide fibers in the entire wiping cloth is 40% by mass or more, and the average number of airborne particles with a diameter of 0.1 μm or more is 10 particles / cm². ２ The following is a wiping cloth.

2. The wiping cloth according to claim 1, wherein the ultrafine polyamide fibers are polyamide fibers obtained by dissolving the alkali-soluble polyester component of a split-type composite fiber that consists of a polyamide component and an alkali-soluble polyester component and is substantially free of a matting agent, and the cross-sectional shape of the fibers is an irregular cross-sectional shape.

3. The wiping cloth according to claim 2, wherein the fibrous structure is a woven fabric in which at least the ultrafine polyamide fibers are used as weft threads.

4. A method for producing a wiping cloth according to claim 1, 2, or 3, comprising the steps of: weaving a fabric using a split composite fiber consisting of a polyamide component and an alkali-soluble polyester component, which is substantially free of a matting agent, as at least the weft; and dissolving the alkali-soluble polyester component by immersing the obtained fabric in an alkaline solution.

5. The number of particles larger than 0.2 μm in liquid after immersion in pure water for 12 hours under Class 100 conditions was 5 particles / ml / cm². ２ The following is the wiping tape.

6. The wiping tape according to claim 5, which is for use with magnetic recording disks.

7. A method for manufacturing a wiping tape, characterized by heat-cutting the fabric for the wiping tape in a cleanroom, and immediately after heat-cutting, using a suction nozzle to suction the smoke generated by the heat-cutting.

8. A method for manufacturing a wiping tape, comprising: a first step of transporting the washed fabric for the wiping tape; a second step of heat-cutting the transported fabric with a first cutting blade; and a third step of transporting the fabric while sucking up the smoke generated by the heat-cutting with a first suction nozzle immediately after the heat-cutting.

9. The method for manufacturing a wiping tape according to claim 8, wherein the first to third steps are performed in a clean room.

10. The method for manufacturing a wiping tape according to claim 8 or claim 9, wherein the distance between the first cutting blade and the first suction nozzle is 30 mm or more and 100 mm or less.

11. A method for manufacturing a wiping tape according to any one of claims 7 to 9, wherein the suction pressure from the first suction nozzle is 0.1 kPa or more and 0.5 kPa or less.

12. A heat-cutting device for wiping tape, comprising a first conveying unit for conveying fabric for wiping tape, a first heat-cutting unit for heat-cutting the fabric conveyed from the first conveying unit, and a second conveying unit for conveying the heat-cut fabric to the next process, wherein a first suction nozzle for sucking particles and smoke from the surface of the fabric is provided between the first heat-cutting unit and the second conveying unit.

13. The wiping tape heat cutting device according to claim 12, further comprising a second heat cutting section after the second conveying section, and a second suction nozzle for sucking up particles and smoke from the surface of the fabric after the second heat cutting section.

Images