Wiping tape, method for manufacturing wiping tape, and heat cutting device

Abstract

To provide a wiping tape with superior cleanliness of the wiping tape itself, and a method for manufacturing a wiping tape. [Solution] When immersed in ultrapure water for 12 hours under Class 100 conditions, the number of particles larger than 0.2 μm in the liquid was 5 particles / ml / cm². 2 The following is the wiping tape. This method of manufacturing wiping tape is characterized by heat-cutting the fabric for the wiping tape in a cleanroom, and immediately after heat-cutting, using a suction nozzle to suck up the smoke generated by the heat-cutting.

Description

[Technical Field]

[0001] This invention relates to a wiping tape, a method for manufacturing a wiping tape, and a heat-cutting device. [Background technology]

[0002] For tapes used to wipe 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 consequently, there is an increasing need for wiping tapes with superior wiping performance to clean these devices. To address these issues, for example, Patent Document 1 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. Furthermore, Patent Document 2 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. Furthermore, Patent Document 3 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 threads to the weft threads is 1.5 to 10 times, and the total fineness of the multifilament yarns made of ultrafine fibers is greater, and the dust generation amount of this 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: Furthermore, Patent Document 4 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. 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. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 5463648 [Patent Document 2] Japanese Patent Publication No. 2022-12698 [Patent Document 3] Japanese Patent Application Publication No. 11-9540 [Patent Document 4] Japanese Patent Publication No. 2017-147017 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, in the case of wiping tapes used in cleanrooms, the actual requirement is to minimize contamination from the wiping tape as much as possible, and currently, there is a need to further improve the cleanliness of the wiping tape itself.

[0005] Therefore, the present invention aims 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. Another objective is to provide a heat-cutting device suitable for use in manufacturing the wiping tapes described above.

[0006] To solve the above problems, the inventors focused on devising a method for melt-cutting the fabric (processed roll) for wiping tape when manufacturing it, and thus obtained the present invention. In other words, the present invention firstly determines that the number of liquid particles larger than 0.2 μm is 5 particles / ml / cm² when immersed in ultrapure water for 12 hours under a Class 100 environment. 2 The following is the wiping tape. Secondly, there is a first wiping tape for magnetic recording disks. Thirdly, the method for manufacturing wiping tape is characterized by heat-cutting the fabric for wiping tape in a clean room, and immediately after heat-cutting, using a suction nozzle to suck up the smoke generated by the heat-cutting. Fourthly, the present invention relates to 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 simultaneously sucking up the smoke generated by the heat-cutting with a first suction nozzle immediately after the heat-cutting. Fifth, the method for manufacturing the wiping tape is to perform the above steps 1 to 3 in a clean room. Sixth, the method for manufacturing the wiping tape described above, wherein the distance between the first cutting blade and the first suction nozzle is 30 mm or more and 100 mm or less. Seventh, the method for manufacturing the wiping tape described above, wherein the amount of suction from the first suction nozzle is 0.1 kPa or more and 0.5 kPa or less. Eighth, the heat-cutting device for wiping tape is characterized by having a first conveying unit for conveying the 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, and having a first suction nozzle between the first heat-cutting unit and the second conveying unit for sucking up particles and smoke from the surface of the fabric. Ninth, a second heat cut portion is provided after the second conveying portion, and a second suction nozzle for sucking particles and smoke on the fabric surface is provided after the second heat cut portion. The wiping tape heat cut device is characterized in that.

Effect of the Invention

[0007] According to the present invention, a wiping tape with improved cleanliness of the tape itself can be obtained.

Brief Description of the Drawings

[0008] [Figure 1] It is an example of a cross-sectional view of the fiber used in the present invention. [Figure 2] It is an example of a cross-sectional view of the fiber used in the present invention.

Embodiment for Carrying out the Invention

[0009] Hereinafter, the present invention will be described in detail.

[0010] First, the present invention is a wiping tape suitable for performing wiping of a magnetic disk or the like in a clean room.

[0011] The wiping tape of the present invention has 5 or less liquid-phase particles of 0.2 μm or more per ml / cm when immersed in ultrapure water for 12 hours or more in an environment of class 100. 2 The following is a wiping tape. By setting the number of particles within such a range, self-dust generation is reduced, the wiping performance on the medium is improved, and residual particles during wiping of the medium are reduced. The number of liquid-phase particles of 0.2 μm or more is preferably 4 or less per ml / cm. 2 The following, and more preferably 3.5 or less per ml / cm. 2 The following.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] Polyethylene terephthalate and polybutylene terephthalate are preferred examples of the polyester components mentioned above.

[0017] Examples of the polyamide components mentioned above include aliphatic polyamides such as polyamide 6, polyamide 6,6, and polyamide 4,6.

[0018] 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.

[0019] 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.

[0020] 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 weight mixing ratio of polyamide MXD6 to polyamide 6 is preferably 35:65 to 70:30.

[0021] 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.

[0022] 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 1000 to 10000 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 value [η]max to the minimum value [η]min of the intrinsic viscosity is 1.0 ≤ [η]max / [η]min ≤ 1.02.

[0023] The metal sulfonate group-containing isophthalic acid component used in the present invention is preferably dimethyl 5-metal sulfisoisophthalate (hereinafter referred to as SIPM) or a compound obtained by esterifying a dimethyl 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, SIPE is preferred. Sodium, potassium, lithium, etc., can be used as the metal in SIPM or SIPE, but sodium is the most preferred. The copolymerization ratio of SIPE is preferably 2.0 to 3.0 mol% of the acid component of the polymer, as this makes it easier to maintain sufficient alkaline solubility and good spinnability.

[0024] Furthermore, polyalkylene glycols are represented by the general formula HO(CnH2nO)mH (where n and m are positive integers), and polyethylene glycol with n=2 (hereinafter referred to as PEG) is the most commonly used and preferred. The molecular weight of the polyalkylene glycol used in the present invention is preferably 1,000 to 10,000, as it is suitable for use in spinning and false-twist processes.

[0025] The copolymerization amount of polyalkylene glycol is preferably 9% by mass or more and 13% by mass or less relative to the polymer, in order to maintain good alkaline water solubility, heat resistance, and oxidation resistance.

[0026] For the above polyester, it is preferable that the ratio of the maximum value [η]max to the minimum value [η]min of the intrinsic viscosity is 1.0 ≤ [η]max / [η]min ≤ 1.02, from the standpoint of operability during spinning and handling in subsequent processes.

[0027] Furthermore, the alkali-soluble polyester component used in the present invention preferably contains 4.7 mol% to 5.7 mol% of diethylene glycol (DEG) in the glycol component, from the viewpoint of alkali solubility, heat resistance, and oxidation resistance.

[0028] 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 the physical force during wiping, causing scratches on magnetic recording media, etc. In addition, trace amounts may be present due to contamination during the manufacturing and processing stages. Even in such cases, if the analytical value using a general ash content measurement method is less than 50 ppm in the polymer, it will not damage the surface during hard disk polishing or cleaning.

[0029] When the above-mentioned composite fibers are subjected to alkaline dissolution processing, the polyester component dissolves completely, causing the fibers to split. Furthermore, heating during this alkaline dissolution process, or through separate heat treatment, causes the polyamide component to shrink, resulting in a high-density, bulky wiping tape.

[0030] The cross-sectional shape of the above-mentioned segmented composite fiber is preferably 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.

[0031] In the case of a split-type composite fiber consisting 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. 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.

[0032] 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.

[0033] 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 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.

[0034] 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.

[0035] Furthermore, if the fibrous structure is a woven fabric, the segmented composite fiber is the weft, warp, or warp thread. It can be used for both latitude and weft directions.

[0036] When using yarn other than split-type composite fibers in either one of the layers, it is preferable to use regular polyester fibers (polyethylene terephthalate fibers) or polyamide fibers for the warp threads.

[0037] In particular, it is preferable that the wiping tape of the present invention uses ultrafine fibers as the weft. Using ultrafine fibers as the weft 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 during weaving.

[0038] In this case, it is preferable to use regular polyester fibers (polyethylene terephthalate fibers) for the warp threads.

[0039] 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 plain weave, and 1500 or more for warp and 1000 or more for satin weave.

[0040]

number

[0041] In the present invention, if the fiber structure 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 tape, for example, an interlock structure is preferred. When the knitted fiber structure of the present invention is used as a wiping tape in a cleanroom, it is preferable to have, for example, a wale count of 70 to 100 threads / 2.54 cm and a course count of 70 to 100 threads / 2.54 cm. In the case of tricot, it is preferable to use approximately 28 g. Furthermore, even if the split-type fibers are used for all of the front yarn, back yarn, and middle yarn, or if only a part of them are split-type fibers, it is more preferable to use them for at least the front and back.

[0042] 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.

[0043] When the fibers are split by alkaline dissolution treatment, oligomers and other substances contained in polyamide and polyester are removed by the alkaline aqueous solution, which reduces the number of self-generated particles in the wiping cloth, making it preferable.

[0044] The alkaline dissolution treatment is a method in which, for example, the split composite fiber of the present invention is immersed in a heated alkaline solution to dissolve the alkali-soluble polyester component and simultaneously shrink the polyamide component, thereby causing the fiber to split. 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, thus reducing the number of self-generated particles in the product.

[0045] 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.

[0046] Furthermore, it is preferable to heat-treat the fiber structure obtained by the above-mentioned alkaline 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, 120-150°C for 0.5-1 hour under moist heat conditions, or 150-190°C for 30 seconds-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.

[0047] In the method for manufacturing the wiping tape of the present invention, it is preferable to use a fiber structure that has been shrunk by 10-20% in the width direction for woven fabrics and 40-60% in the width direction for knitted fabrics by performing the above-described processes on the raw fabric obtained through processes such as weaving and knitting. 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 being W0 and the length being L0, and the width after shrinkage being W and the length being L. It can be calculated using the formula 100 × {(W0 - W) / (W0)} (%).

[0048] Then, 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 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 processed roll (fabric for wiping tape). Subsequently, the desired wiping tape can be obtained by melt cutting or other methods. The obtained wiping tape can be sealed in a resin film pack. When using this sealed pack in the manufacturing process of hard disks, etc., it can be opened and used as wiping tape.

[0049] In the present invention, the processed fabric obtained by the above methods is melt-cut into a tape shape using a slitting method so that dust is not generated from the wiping tape itself. When melt-cutting the above-mentioned processed fabric using a slitting method, heat cutting is the mainstream method. However, cutting with heat inevitably generates some smoke, which can contaminate the wiping tape after cutting. Therefore, in the manufacturing method of the wiping tape of the present invention, measures are taken when heat cutting to reduce contamination of the wiping tape after cutting and to reduce self-dusting.

[0050] In the present invention, it is preferable to perform the heat cutting in a cleanroom. Furthermore, it is 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.

[0051] 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.

[0052] 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 a disc, 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.

[0053] 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.

[0054] Furthermore, in the present 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 reduced particle count, even when cut to a narrow width, as there is no fraying at the cut edges, resulting in less dust generation during manufacturing and use, and a higher level of cleanliness with less contamination.

[0055] 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. By using a suction nozzle to suck up 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 level of cleanliness with minimal contamination. To improve the cleaning effectiveness of the wiping tape, the entire surface of the fabric may be vacuumed by using an additional suction nozzle.

[0056] 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 amount 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. When a second suction nozzle is provided, the distance between the first suction nozzle and the second suction nozzle is preferably 30 mm to 100 mm, and the suction amount from the second suction nozzle is preferably 0.1 kPa to 0.5 kPa, as 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, as well as maintaining the cleanliness of the wiping tape and obtaining excellent wiping performance. Furthermore, to achieve superior cleanliness, it is preferable to perform heat cutting and suction within a cleanroom.

[0057] Furthermore, in order to manufacture the wiping tape as described above, a heat cutting device may be used that has 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, and a first suction nozzle for sucking up particles from the surface of the fabric between the first heat cutting unit and the second conveying unit. Furthermore, the heat cutting device may include a second heat cutting section after the second conveying section, and a second suction nozzle after the second heat cutting section for sucking up particles and smoke from the surface of the fabric. This can improve the efficiency of heat cutting and conveying.

[0058] Although a suction nozzle was used in the above example, a suction device that is not nozzle-shaped may also be used.

[0059] Using the manufacturing method described above, the number of particles larger than 0.2 μm in the liquid after immersion in ultrapure water for 12 hours under a Class 100 environment is 5 particles / ml / cm². 2 The following wiping tape can be obtained.

[0060] The breaking strength of the fabric constituting the wiping tape is preferably 800N or more, and more preferably 1000N or more.

[0061] 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.

[0062] 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 an even better result, making it less prone to contamination and easier to obtain a product with excellent wiping properties. Here, the number of airborne particles with a diameter of 0.1 μm or more is the value measured below. A 1cm wide tape-like wiping cloth is cut to a length of 20cm to be used as a sample. In a Class 100 cleanroom, the sample is placed on the measuring stage of a surface particle detector (Pentagon Technologies QIII Ultra®) with both ends fixed using a jig, and the total number of particles between 0.1μm and 5μm in diameter on the sample surface 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 0.1μm or larger (the unit of total particles is particles / cm). 2 ).

[0063] 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.

[0064] The wiping tape of the present invention may contain 30% or more 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. [Examples]

[0065] The present invention will be specifically described below with reference to examples. It is not limited to that.

[0066] Furthermore, the evaluation methods are as follows:

[0067] <Intrinsic viscosity of polyester> The intrinsic viscosity [η] is 2 in a mixed solvent of phenol / tetrachloroethane = 6 / 4 (mass ratio). The viscosity was measured using an automatic viscometer at 0°C by a conventional method.

[0068] <Relative viscosity of polyamide> The relative viscosity ηrel was measured by a conventional method using an Ostwald viscometer at 20 °C in a sulfuric acid solvent. This was done.

[0069] <Measurement of the number of particles in the liquid> As a sample, prepare a tape cut to about 1.25 m 2 (for a 12.5 mm width, 10 m). Immerse the cut tape in 400 ml of ultrapure water and let it stand in a running clean bench for 12 hours or more. Take out the immersed sample with washed tweezers, let it stand for 5 minutes or more, and then measure the particles in the liquid using a particle counter (KS-28b) manufactured by RION. Divide the obtained particle number result by the ultrapure water volume and the fabric surface area, and calculate the number of particles per unit (particles / ml / cm 2 ). All operations associated with the measurement were carried out in a class 100 clean room.

[0070] [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 oxide) was used. On the other hand, as the alkali-soluble polyester component, a copolymerized polyethylene terephthalate with an intrinsic viscosity of 0.77 and substantially free of a matting agent (mainly composed of terephthalic acid and ethylene glycol, containing 2.3 mol% of SIPE in the acid component, 10 mass% of polyethylene glycol with an average molecular weight of 8000, and 5.5 mol% of DEG) was used. The volume ratio of segment 1 that branches radially and segment 2 that replenishes the radial part is 3:7. The melt composite spinning was carried out at a spinning temperature of 295 °C and a spinning speed of 1050 m / min so that the alkali-soluble polyester component constitutes segment 1 that branches radially and the polyamide component constitutes segment 2 that replenishes the radial part, and an undrawn yarn with the same fiber cross-sectional shape as in Figure 2 was obtained. Then, the obtained undrawn yarn was drawn at a roller heater temperature of 85 °C, a plate heater temperature of 150 °C, and a draw ratio of 3.0 times to obtain a split-type composite fiber of 84 dtex / 25f. Then, using this drawn yarn as the weft and regular polyester fibers (intrinsic viscosity 0.61, 84 dtex / 36f) spun using polyethylene terephthalate without a matting agent as the warp, a back satin fabric was obtained. The obtained fabric was immersed in a 2 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. In addition, the polyamide fiber content in the entire obtained wiping cloth was 40 mass%. The processed fabric was brought into a cleanroom. The processed fabric was heat-cut so that the weft direction was the width direction to create 1 cm wide webbing 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 having a first cutting blade, a first suction unit having a first suction nozzle, a second conveying unit, a second heat cutting unit having a second cutting blade, and a second suction unit having 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 rate 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 that, it was heat-cut with the second cutting blade, and then suctioned at a rate of 0.14 kPa using the second suction nozzle at a distance of 5 cm from the cutting blade to obtain a wiping tape. When the wiping tape was immersed in ultrapure water for 12 hours under Class 100 conditions, the number of particles larger than 0.2 μm in the liquid was 3.5 / ml / cm³. 2 When we evaluated its wiping ability on media, we found that it had excellent wiping properties and did not generate any dust.

[0071] [Example 2] Except for changing the cut width to 2 cm, a wiping tape was obtained in the same manner as in Example 1. When the wiping tape was immersed in ultrapure water for 12 hours under Class 100 conditions, the number of particles larger than 0.2 μm in the liquid was 3.6 / ml / cm³. 2 When we evaluated its wiping ability on media, we found that it had excellent wiping properties and did not generate any dust.

[0072] [Example 3] A wiping tape was obtained in the same manner as in Example 1, except that the suction volume of the first suction nozzle was set to 0.4 kPa. The number of particles in the liquid was 5 / ml / cm 2 It was less than [amount missing]. When the media was evaluated for wiping performance, it showed excellent wiping ability and did not generate any self-generated dust.

[0073] [Comparative Example 1] 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.

[0074] [Comparative Example 2] 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.

[0075] [Comparative Example 3] A wiping tape was obtained in the same manner as in Example 1, except that the suction amount of the first suction nozzle was set to 0.05 kPa.

[0076] [Comparative Example 4] A wiping tape was obtained in the same manner as in Example 1, except that the suction amount of the first suction nozzle was set to 0.7 kPa.

[0077] The wiping tapes in Examples 1-3 were wiping tapes with low self-generating dust and high cleanliness. The wiping tape obtained from Comparative Example 1 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 and prevented the formation of a clean cut molten surface. Self-dusting occurred during media use, and the wiping performance was inferior to that of the example product. The wiping tapes obtained from Comparative Examples 2 and 3 had a particle count of 5 / ml / cm² in liquid. 2 It exceeded the limit. Compared to the example product, the wiping tape had inferior wiping properties and self-dusting properties. The wiping tape obtained from Comparative Example 4 had a large suction volume from 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 example product. [Industrial applicability]

[0078] The wiping tape of the present invention has excellent wiping properties, generates little self-dust, and has superior cleanliness, making it suitable for use with precision equipment such as magnetic recording media like hard disks. [Explanation of Symbols]

[0079] 1. Radially branching segments 2. Segments that supplement the radial portion

Claims

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

2. The wiping tape according to claim 1, for use with magnetic recording disks.

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

4. 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.

5. The method for manufacturing a wiping tape according to claim 4, wherein the first to third steps are performed in a clean room.

6. A method for manufacturing a wiping tape according to claim 4 or 5, wherein the distance between the first cutting blade and the first suction nozzle is 30 mm or more and 100 mm or less.

7. A method for manufacturing a wiping tape according to any one of claims 4 to 6, wherein the amount of suction from the first suction nozzle is 0.1 kPa or more and 0.5 kPa or less.

8. 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.

9. The wiping tape heat cutting device according to claim 8, 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.

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