JP6364919B2 - Sheet material and method for producing the same - Google Patents

Description

  The present invention is a sheet-like material including a fiber entangled body made of ultrafine fibers, the surface of which is covered with napped hairs made of ultrafine fibers, and preferably a polymer elastic body contributes at least to the gripping property of the fibers. In particular, the present invention relates to a sheet-like material having excellent performance as an abrasive cloth suitably used for polishing and / or cleaning.

  Conventionally, various types of sheet-like materials have been examined by applying ultrafine fiber ultrafine technology.

In the field of artificial leather, it is well known that the single fiber fineness of the fiber is made fine as a method for obtaining an artificial leather having a soft touch and excellent texture. The number average single fiber fineness is 1.3 × 10 ^{−5 to} 3.2 × 10 ⁻⁴ dtex, and the single fiber fineness ratio is 1.3 × 10 ^{−5 to} 3.2 × 10 ⁻⁴ dtex. There has been proposed a nanofiber artificial leather formed from a nanofiber aggregate whose sum is 60% or more (see Patent Document 1). However, in this proposal, since the variation of the single fiber fineness is large, the napped length becomes non-uniform, and it is difficult to obtain an elegant surface of the artificial leather and a soft surface touch. Furthermore, in this proposal, there is no proposal for a method of buffing without aggregation or fusion between fibers, and therefore it is not possible to raise.

  In the field of suede-like artificial leather, the average single fiber fineness of the fibers constituting the napped is 0.0001 to 0.5 dtex, and the fibers constituting the napped account for 70 to 100% of the surface, and the average napped fiber The length is 200 to 1000 μm, and a part of the polymer elastic body penetrates from the outer peripheral portion of the ultrafine fiber bundle constituting the fiber entanglement to the inside of the ultrafine fiber in an area ratio of 1 to 30%. Suede-like artificial leather, which is characterized by the above, has been proposed (see Patent Document 2).

  In this proposal, it is possible to obtain a suede-like artificial leather with a good texture without adjusting the surface properties and maintaining the surface properties by adjusting the existence state of the polymer elastic body inside the ultrafine fiber bundle and the raised state. it can. However, this proposal is only for thick fibers with an average single fiber fineness of 0.03 to 0.2 dtex.

  Further, in the field of magnetic recording disks, with the recent increase in storage density, smoothing of the disk surface to the limit is required. And in recent recording methods for magnetic recording disks, vertical recording media in which the easy axis of magnetization in the magnetic film is oriented in the vertical direction are mainly used, so there are irregularities and scratches on the substrate before forming the magnetic layer. There is a possibility that the easy axis of magnetization becomes an abnormally tilted part after the magnetic film is formed. In order to deal with such problems, the disk surface before the formation of the magnetic film is required to have a substrate surface roughness of 0.2 nm or less and to minimize scratches on the substrate surface called scratch defects. In the recording method developed after the perpendicular recording medium, the requirement for the substrate before forming the magnetic layer is the smoothing to the limit as described above. Therefore, a polishing cloth made of ultrafine fibers is used in the polishing and / or cleaning of the substrate.

  In view of the background as described above, a nonwoven fabric formed by entangled polyamide ultrafine fibers having an average single fiber diameter of 0.5 to 4 μm or less and a fiber diameter CV value of 10% or less, a polymer elastic body, Has been proposed (see Patent Document 3). According to this proposed polishing cloth, the scraping effect of ultrafine fibers is greatly improved, and scratch defects tend to be suppressed. However, as the accuracy of the substrate surface roughness has been further improved due to the recent significant increase in density, the minimization of foreign matter has further progressed. With ultrafine fibers having a single fiber diameter of about 1.4 μm used in this proposal, The removal effect was not sufficient.

  In view of the background as described above, a non-woven structure having a uniform surface state in which an ultrafine fiber of 0.3 dtex or less is entangled and contains 15 to 80% by mass of an elastomer with respect to the mass of the fiber. A tape for processing a magnetic recording medium has been proposed which has napped fibers of 0.3 dtex or less on its surface and a wear resistance coefficient of 20 mg or less (see Patent Document 4). However, this proposal is actually for 0.02 decitex thick fibers as ultrafine fibers, and unless the polyurethane elastomer, which causes scratches, is added to 15 to 80% by mass, the abrasion resistance There was a problem that the coefficient could not be 20 mg or less.

Japanese Patent Laid-Open No. 2004-256983 JP 2008-280643 A JP 2004-299041 A JP 2000-242921 A

  Therefore, in view of the actual state of the above-mentioned conventional technology, the object of the present invention is to obtain a napped surface in which nanofiber-level ultrafine fibers are arranged extremely densely, and thereby to hold the fiber in an elegant surface state with an extremely soft surface touch. Is to provide a good sheet-like material and a method for producing the same.

  Another object of the present invention is to provide a polishing cloth and a method for producing the same, which are suitably used especially for polishing and / or cleaning.

The present invention is to solve the above-mentioned problem, and the sheet-like material of the present invention comprises a fiber-entangled body mainly composed of ultrafine fibers having an average single fiber diameter of 50 to 800 nm. The amount of the polymer elastic body with respect to the mass of the ultrafine fiber is 5 % by mass or less, and one side or both sides of the sheet-like material is composed of napped surfaces, and among the napped surfaces, at least the transverse direction of the linear density of the fibers arranged in the longitudinal direction in the one surface 12/10 [mu] m width and 150 lines / I 10 [mu] m width der linear density in the lateral direction of the fibers arranged in the longitudinal direction 12/10 [mu] m piloerection coverage of the surface is the width 150 present / 10 [mu] m width of sheet material and wherein 70% to 99% der Rukoto.

  According to a preferred embodiment of the sheet-like material of the present invention, the average single fiber diameter of the ultrafine fibers is 50 to 450 nm.

  According to the preferable aspect of the sheet-like material of the present invention, the single fiber diameter CV value of the ultrafine fiber is 0.1 to 10%.

  According to a preferred embodiment of the sheet material of the present invention, the sheet material of the present invention does not contain a polymer elastic body.

  According to a preferred embodiment of the sheet-like material of the present invention, the amount of weight loss of the seafer on the surface where the linear density in the horizontal direction of the fibers arranged in the vertical direction is 12/10 μm width to 150/10 μm width is 30 mg or less. It is.

  The sheet-like material of the present invention is suitably used for an abrasive cloth.

The method for producing the sheet-like material of the present invention is a sheet-like material comprising a fiber entanglement mainly composed of ultrafine fibers having an average single fiber diameter of 50 to 800 nm, and is a polymer with respect to the mass of the ultrafine fibers. It is a method for producing a sheet-like product, characterized in that a sheet having an elastic body weight of 5 % by mass or less is buffed with a solution with the surface or the entire sheet wet.

  According to the present invention, by arranging nanofiber-level ultrafine fibers very densely, a sheet-like material having excellent fiber gripping properties can be obtained with an extremely soft surface touch and an elegant surface state. By using the sheet-like material of the present invention, particularly when polishing and / or cleaning is performed, the surface roughness is minimized, the ability to scrape out minimal foreign matters remaining on the substrate surface, and the substrate for the magnetic recording medium A polishing cloth excellent in reducing the defective rate is obtained.

The sheet-like material of the present invention is a sheet-like material comprising a fiber entangled body mainly composed of ultrafine fibers, and preferably composed of a polymer elastic body. Specifically, the sheet-like material of the present invention comprises a fiber entangled body mainly composed of ultrafine fibers having an average single fiber diameter of 50 to 800 nm, and the amount of the polymer elastic body with respect to the mass of the ultrafine fibers is The sheet-like material is 5 % by mass or less, and one or both surfaces of the sheet-like material are constituted by napped surfaces, and the linear density of fibers arranged in the vertical direction on at least one surface of the napped surfaces in the horizontal direction. There I sheet der of 12/10 [mu] m width and 150 present / 10 [mu] m width, the linear density of the transverse direction of the fibers arranged in the longitudinal direction is a surface of a 12/10 [mu] m width and 150 present / 10 [mu] m width piloerection coverage Ru 70% to 99% der.

  In the present invention, it is important that the average single fiber diameter of the ultrafine fibers is 50 to 800 nm. By setting the average single fiber diameter to 800 nm or less, preferably 650 nm or less, more preferably 450 nm or less, the fiber gripping force is excellent with high density, and the surface touch is a sheet-like material made of conventional ultrafine fibers. In particular, when used as a polishing cloth, a polishing cloth capable of achieving high-precision finishing can be obtained.

  Further, by setting the average single fiber diameter to 50 nm or more, preferably 100 nm or more, a sheet-like product having high single fiber strength and rigidity is obtained, and high grinding performance is manifested particularly when used as an abrasive cloth. If the average single fiber diameter is less than 50 nm, it is very difficult to aggregate and open the ultrafine fiber aggregate, the raised quality is remarkably lowered, and the desired surface touch cannot be obtained. Doing so may cause scratches.

  In particular, regarding the uniformity of the single fiber diameter, the fiber diameter CV value of the ultrafine fiber is preferably 10% or less. The fiber diameter CV value here is the percentage (%) of the value obtained by measuring the average single fiber diameter of any 100 ultrafine fibers, calculating the average value and standard deviation, and dividing the standard deviation by the average value. The smaller this value is, the more uniform it is. By setting the fiber diameter CV value to 10% or less, it is possible to obtain a sheet-like material having a smooth surface appearance and an extremely soft surface touch with uniform napping, and particularly with an abrasive cloth, uniform pressing force and abrasive dispersion. Depending on the property, high-precision polishing is possible.

  Further, when the fiber diameter CV value is smaller than 0.1%, the surface appearance becomes artificial like instead of natural like because the uniformity is excessive, resulting in poor elegance. In particular, in the polishing cloth, when the uniformity is excessive, a friction caused by frictional heat is generated due to an increase in friction during polishing. A more preferable fiber diameter CV value is 0.5% to 9.0%.

  As will be described later in the measurement method of the examples, when fibers having a fiber diameter exceeding 5 μm are mixed, the fibers are excluded from the measurement target of the average fiber diameter as not corresponding to the ultrafine fibers. .

  Examples of the polymer that forms ultrafine fibers include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate and polylactic acid, polyamides such as 6-nylon and 66-nylon, acrylic, polyethylene, polypropylene, and thermoplastic cellulose. And thermoplastic resins that can be melt-spun. Among these, polyester is preferably used from the viewpoint of strength, dimensional stability, and light resistance.

  Moreover, it is a preferable aspect that it is the fiber obtained from a recycling raw material or a plant-derived raw material from a viewpoint of environmental consideration. Polycondensation polymers typified by polyesters and polyamides constituting fibers often have high melting points and are excellent in heat resistance against heat, and are preferably used. In particular, the fibers made of polyamides have particularly good compatibility with the slurry liquid, have excellent retention and dispersibility of the abrasive grains in the slurry liquid, and polish without damaging non-polished materials. In addition, since it has excellent flexibility and low contact resistance with an object to be polished, it is suitably used for fine polishing. Further, the ultrafine fibers can be configured by mixing fibers of different materials.

  In addition, the polymer constituting the ultrafine fibers may be copolymerized with other components, and may contain additives such as particles, flame retardants, and antistatic agents.

  As the cross-sectional shape of the ultrafine fiber, for example, a polygon such as a circle, an ellipse, a flat shape, and a triangle, a fan, a cross, Y, H, X, W, C, and a π type can be used.

  It is a preferable aspect that the ultrafine fibers constituting the fiber entangled body take the form of an ultrafine fiber bundle. As a form of the ultrafine fiber bundle, the ultrafine fibers may be slightly separated from each other, may be partially bonded, or may be aggregated.

  The fiber entangled body used in the sheet-like product of the present invention may be either a short fiber entangled body or a long fiber entangled body, but a short fiber entangled body is preferably used in terms of compressibility and quality.

  As a short fiber entangled body used in the sheet-like material of the present invention, a short fiber nonwoven fabric obtained by applying a needle punch or a water jet punch after forming a laminated web using a card and a cross wrapper, A long fiber nonwoven fabric obtained from a spunbond method or a melt blow method, a nonwoven fabric obtained by a papermaking method, or the like can be appropriately employed.

  Among these, the short fiber nonwoven fabric and the spunbond nonwoven fabric can obtain the form of the ultrafine fiber bundle as described later by needle punching. The fiber length of the short fiber in the short fiber nonwoven fabric is preferably 25 to 90 mm. By setting the fiber length to 25 mm or more, a sheet-like material having excellent abrasion resistance can be obtained by entanglement. Moreover, by setting the fiber length to 90 mm or less, it is possible to obtain a sheet-like material excellent in compression characteristics and surface quality of the sheet-like material. The fiber length is more preferably 30 to 80 mm.

  The fiber entangled body used in the present invention can include a reinforcing layer for the purpose of improving the strength. As the reinforcing layer, woven fabrics, knitted fabrics, nonwoven fabrics (including paper), and film-like materials such as plastic films and metal thin film sheets can be employed. In the case of a woven or knitted fabric in which the reinforcing layer is composed of fibers, the average single fiber diameter of the fibers is preferably about 0.1 to 20 μm.

  The sheet-like material of the present invention has a raised surface composed of the above-mentioned ultrafine fibers on at least one side, and the linear density of fibers arranged in the vertical direction on at least one side of the raised surfaces is 12/10 μm. It is important that the width is ˜150 / 10 μm. By setting the line density to 12/10 μm width or more, preferably 20/10 μm or more, it becomes dense napped, has an elegant surface appearance, has an extremely soft surface touch, and does not easily lose fibers. You can get things. In particular, the polishing cloth is a preferable mode because the wiping performance is improved. When the linear density is higher than 150/10 μm, the tactile sensation of each ultrafine fiber cannot be recognized, and the surface touch feels rough. In particular, in the polishing cloth, the degree of freedom of the space between the ultrafine fibers decreases, and the slurry cannot be dispersed, which causes scratches. Further, in the production of a sheet-like product, the openability of the ultrafine fibers is significantly reduced. By setting the linear density CV value to 40% or less, more preferably 30% or less, the above-described effect of the linear density is sufficiently exhibited.

  In the present invention, the linear density in the horizontal direction of the fibers arranged in the vertical direction is defined as the degree of orientation of the ultrafine fibers on the raised surface where at least one surface thereof is a raised surface made of the ultrafine fibers. That is, the napped direction with a high degree of orientation is the vertical direction, and the orthogonal direction is the horizontal direction. Then, using the surface of the sheet-like material as an observation surface, 30 images of the sheet-like material with an observation magnification of 5000 times are taken with a scanning electron microscope (SEM). From the photographed image, avoid a portion where a polymer elastic body such as polyurethane is exposed on the surface and no ultrafine fiber is present, or a portion where a large hole is formed by a needle punch or the like, and a reference line of 10 μm is aligned in the horizontal direction. Draw a place. Lines in the horizontal direction of the fibers arranged in the vertical direction by calculating the average value of n number 30 by measuring the number of ultra fine fibers having an acute angle of 60 ° or more intersecting with the reference line in the vertical direction. Density. Further, the linear density CV value is calculated from the standard deviation value and the average value with n number of 30 as a population.

The sheet-like material of the present invention has a napped coverage ratio of 70 to 99% on the surface where the line density of the fibers arranged in the vertical direction is 12/10 μm width to 150/10 μm width. is important. Good Mashiku is 80 to 99%. When the napped coverage is less than 70%, the entangled fibers that are not napped are pulled out by an external force, which may cause the fibers to fall off, and the surface quality becomes uneven. Further, since the wiping performance is lowered, the performance is inferior particularly when an abrasive cloth is used. The napped coverage is the presence of napped fibers on a surface where the line density in the horizontal direction of the fibers arranged in the vertical direction is 12/10 μm to 150/10 μm wide by a scanning electron microscope (SEM). As can be seen, the observation magnification was increased to 30 to 70 times, and the ratio of the total area of the napped parts per total area of 4 mm ² was calculated using image analysis software, and the napped coverage was obtained. The ratio of the total area can be calculated by binarizing the captured SEM image using the image analysis software ImageJ with the raised portion and the non-raised portion set to the threshold value 100. In the calculation of the napped coverage, if a substance that is not napped is calculated as napped and greatly affects the napped coverage, the image is manually edited and the portion is calculated as a non-napped portion.

  Image analysis software ImageJ is exemplified as the image analysis system. However, the image analysis system is not limited to image analysis software ImageJ as long as the image analysis system includes image processing software having a function of calculating the area ratio of a prescribed pixel. . The image processing software ImageJ is a common software and was developed by the National Institutes of Health. The image processing software ImageJ has a function of specifying a necessary region for the captured image and performing pixel analysis.

  In the sheet-like material of the present invention, a large number of gaps of several nanometers to 500 nm are created between single fibers or intertwined fibers, and thus may exhibit specific properties such as a porous material, such as a filter. It can also be used as an application.

  In the sheet-like material of the present invention, the amount of the polymer elastic body with respect to the mass of the ultrafine fiber of the fiber entangled body is 15% by mass or less. By including the polymer elastic body, it is possible to impart an appropriate compressive property to the sheet-like material. On the other hand, when the amount of the polymer elastic body is more than 15% by mass, the fiber in the napping process The spreadability becomes poor, and the flexibility of the sheet-like material decreases. In particular, in the porous material described above, the size of the gap is not uniform, so that the porous property is poor. Further, the wear resistance is improved by setting the amount of the polymer elastic body to 15% by mass or less. In an ordinary entangled body of ultrafine fibers, if the amount of the polymer elastic body is reduced, the gripping force of the ultrafine fiber by the polymer elastic body is weakened, so the wear resistance is not improved. On the other hand, in the sheet-like material of the present invention, very fine ultrafine fibers having an average single fiber diameter of 50 to 800 nm are entangled in a continuous state in the ultrafine fiber bundle, and the surface state is dense and uniform. It is possible to reduce the amount of the polymer elastic body while maintaining the gripping force, and the wear resistance is improved.

In terms of environmental considerations, it is not preferable to add a large amount of a polymer elastic body because the amount of organic substances used in the production process increases, and a smaller amount of the polymer elastic body can be obtained from recycled materials and plant-derived materials. When fibers are used, it is easy to recover and discard . In the present invention, the high molecular elastic member is shall be included in 5 mass% or less with respect to ultrafine fibers by weight, it may be better to not include the elastic polymer. For example, when a sheet-like material is used after being dyed, there is a difference in color tone between the fiber entangled fiber after dyeing and the polymer elastic body, and therefore it may be preferable that the number of polymer elastic bodies is small. In the case of the polishing cloth, since the surface is made only of fibers because the polymer elastic body is not included, scratch defects caused by the polymer elastic body scraping the object to be polished are reduced.

  In the above-mentioned polymer elastic body, if necessary, pigments such as carbon black, dyes, antifungal agents and antioxidants, UV absorbers, light stabilizers such as light stabilizers, flame retardants, penetrants and lubricants, Anti-blocking agents such as silica and titanium oxide, surfactants such as water repellents, viscosity modifiers and antistatic agents, antifoaming agents such as silicone, fillers such as cellulose, and coagulation regulators, silica and titanium oxide, etc. Inorganic particles or the like can be contained.

  Examples of the polymer elastic body used in the present invention include polyurethane elastomers, polyureas, polyacrylic acid, ethylene / vinyl acetate elastomers and acrylonitrile / butadiene elastomers and styrene / butadiene elastomers, polyvinyl alcohol, and polyethylene glycol. From the viewpoint of compression characteristics, polyurethane elastomers are preferably used. The polymer elastic body can contain a plurality of polymer elastic bodies.

  As the polyvinyl alcohol, polyvinyl alcohol having a saponification degree of 80% or more is preferably used.

  Examples of the polyurethane elastomer used in the present invention include polyurethane and polyurethane / polyurea elastomer.

  As the polyurethane elastomer used in the present invention, either a solvent-based polyurethane elastomer or a water-dispersed polyurethane elastomer can be used.

  As the polyurethane elastomer used in the present invention, a polyurethane elastomer obtained by a reaction of a polymer diol, an organic diisocyanate and a chain extender is preferably used.

  As the polymer diol, for example, a polycarbonate diol, a polyester diol, a polyether diol, a silicone diol, and a fluorine diol can be employed, and a copolymer combining these can also be used. Among these, from the viewpoint of hydrolysis resistance, it is preferable to use a polycarbonate diol and a polyether diol.

  The polycarbonate-based diol can be produced by transesterification of alkylene glycol and carbonate, or reaction of phosgene or chloroformate with alkylene glycol.

  Examples of the alkylene glycol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, and the like. Linear alkylene glycol, and branched alkylene glycols such as neopentyl glycol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol and 2-methyl-1,8-octanediol Alicyclic diols such as 1,4-cyclohexanediol, aromatic diols such as bisphenol A, glycerin, trimethylolpropane, and pentaerythritol. In the present invention, both polycarbonate-based diols obtained from individual alkylene glycols and copolymerized polycarbonate-based diols obtained from two or more types of alkylene glycols can be employed.

  Examples of the polyester diol include polyester diols obtained by condensing various low molecular weight polyols and polybasic acids.

  Examples of the low molecular weight polyol include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, and 2,2-dimethyl-1,3-propane. Diol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexane-1,4-diol, and One kind or two or more kinds selected from cyclohexane-1,4-dimethanol can be used.

  Further, addition products obtained by adding various alkylene oxides to bisphenol A can also be used.

  Polybasic acids include, for example, succinic acid, maleic acid, adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, and hexahydro One kind or two or more kinds selected from isophthalic acid can be mentioned.

  Examples of the polyether-based diol used in the present invention include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and copolymer diols obtained by combining them.

  The number average molecular weight of the polymer diol is preferably in the range of 500 to 4000 when the molecular weight of the polyurethane-based elastomer is constant. By making the number average molecular weight preferably 500 or more, more preferably 1500 or more, it is possible to prevent the sheet-like material from becoming hard. Moreover, the intensity | strength as a polyurethane-type elastomer is maintainable by making a number average molecular weight into 4000 or less, More preferably, 3000 or less.

  Examples of the organic diisocyanate used in the present invention include aliphatic diisocyanates such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate and xylylene diisocyanate, and aromatic diisocyanates such as diphenylmethane diisocyanate and tolylene diisocyanate. These can also be used in combination. Among these, aliphatic diisocyanates such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate and isophorone diisocyanate are preferably used from the viewpoint of light resistance.

  As the chain extender, amine chain extenders such as ethylenediamine and methylenebisaniline, and diol chain extenders such as ethylene glycol can be preferably used. Moreover, the polyamine obtained by making polyisocyanate and water react can also be used as a chain extender.

  The polyurethane used in the present invention can be used in combination with a crosslinking agent for the purpose of improving water resistance, abrasion resistance, hydrolysis resistance and the like. The cross-linking agent may be an external cross-linking agent added as a third component to the polyurethane-based elastomer, or may be an internal cross-linking agent that introduces a reactive site that becomes a cross-linked structure in the polyurethane molecular structure in advance. It is preferable to use an internal cross-linking agent because cross-linking points can be formed more uniformly in the polyurethane molecular structure and the reduction in flexibility can be reduced.

  As the crosslinking agent, compounds having an isocyanate group, an oxazoline group, a carbodiimide group, an epoxy group, a melamine resin, a silanol group, and the like can be used.

  In addition, when the polyurethane elastomer used in the present invention is a water-dispersed polyurethane elastomer, it is a preferred embodiment that has a hydrophilic group in the molecular structure. By including a hydrophilic group in the molecular structure, dispersion and stability as a water-dispersed polyurethane elastomer can be improved.

  Examples of the hydrophilic group include any one of a cationic group such as a quaternary amine salt, a combination of an anionic hydrophilic group such as a sulfonate and a carboxylate, and a combination of an anionic and nonionic hydrophilic group. Hydrophilic groups can also be employed.

  Of these, nonionic hydrophilic groups that are free from yellowing caused by light and harmful effects caused by a neutralizing agent are particularly preferably used. That is, in the case of an anionic hydrophilic group, a neutralizing agent is required. For example, the neutralizing agent is a tertiary amine such as ammonia, triethylamine, triethanolamine, triisopropanolamine, trimethylamine and dimethylethanolamine. In some cases, amines are generated and volatilized by heat during film formation or drying, and released outside the system. For this reason, in order to suppress the release of air and the deterioration of the working environment, it is essential to introduce a device for recovering volatile amines.

  In addition, when the amine does not volatilize by heating and remains in the final product sheet, it may be discharged to the environment when the product is incinerated. On the other hand, in the case of a nonionic hydrophilic group, since no neutralizing agent is used, it is not necessary to introduce an amine recovery device, and there is no fear of remaining amine in the sheet. In addition, when the neutralizing agent is an alkali metal such as sodium hydroxide, potassium hydroxide and calcium hydroxide, or a hydroxide of an alkaline earth metal, the polyurethane part becomes alkaline when wetted with water, In the case of a nonionic hydrophilic group, since a neutralizing agent is not used, there is no need to worry about degradation due to hydrolysis of the polyurethane elastomer.

The apparent density of the sheet-like material of the present invention is preferably 0.10 to 0.80 g / cm ³ , more preferably 0.20 to 0.65 g / cm ² . When the apparent density is 0.10 g / cm ³ or more, the denseness and mechanical properties of the sheet-like material are good, and when the apparent density is 0.80 g / cm ³ or less, it is possible to prevent the texture from becoming hard.

  The thickness of the sheet is preferably 0.1 to 10 mm. By setting this thickness to 0.1 mm or more, preferably 0.3 mm or more, it is excellent in the form stability and dimensional stability of the polishing cloth, and it is possible to suppress the occurrence of processing irregularities and scratch defects due to the elongation of the polishing cloth. . On the other hand, when the thickness is 10 mm or less, more preferably 5 mm or less, the pressing pressure of the polishing pad can be sufficiently propagated.

  Next, an example of a method for producing the sheet-like material of the present invention will be described.

  As a means for obtaining a nonwoven fabric such as a fiber entangled body in which ultrafine fiber bundles are entangled, it is preferable to use ultrafine fiber generating fibers such as sea-island fibers. Although it is difficult to manufacture a nonwoven fabric such as a fiber entangled body directly from an ultrafine fiber, a fiber entangled body is manufactured from an ultrafine fiber generating fiber, and an ultrafine fiber generating fiber such as a sea-island fiber in the fiber entangled fiber is manufactured. By generating fibers, it is possible to obtain a fiber entangled body in which ultrafine fiber bundles are entangled.

  For sea-island type fibers, sea-island type composite fibers that use a sea-island type composite base to spun two components of the sea component and the island component, and mixed spinning that mixes and spins the two components of the sea component and the island component are spun. Examples thereof include fibers. Among these sea-island-type fibers, it is possible to obtain ultrafine fibers controlled with high accuracy, and to obtain a sufficiently long ultrafine fiber, which contributes to the strength of the nonwoven fabric and the sheet-like material having the nonwoven fabric. Therefore, sea-island type composite fibers are preferably used.

  In the present invention, the number of fibers in the ultrafine fiber bundle is preferably 300 to 9000 fibers / bundle, more preferably 300 to 8500 fibers / bundle. When the number of fibers is less than 300 / bundle, the fineness of the ultrafine fibers is poor, and for example, mechanical properties such as wear tend to be reduced. Moreover, when there are more than 9000 fibers / bundle, the openability at the time of napping falls, and there exists a tendency for the fiber distribution of a napped surface to become non-uniform | heterogenous.

  Examples of the sea component of the sea-island fiber include polyethylene, polypropylene, polystyrene, copolymer polyester obtained by copolymerizing sodium sulfoisophthalate, polyethylene glycol, and the like, polylactic acid, and PVA.

  The fiber ultrafine treatment (sea removal treatment) of the sea-island fiber can be performed by immersing the sea-island fiber in a solvent and squeezing the solution. As the solvent for dissolving the sea component, when the sea component is polyethylene, polypropylene, or polystyrene, an organic solvent such as toluene or trichloroethylene is used. Further, when the sea component is a copolyester or polylactic acid, an alkaline aqueous solution such as sodium hydroxide is used.

  In addition, for the fiber ultrafine treatment, apparatuses such as a continuous dyeing machine, a vibro-washer type seawater removal machine, a liquid dyeing machine, a Wins dyeing machine, and a jigger dyeing machine can be used.

  The sea component can be dissolved and removed at any timing before the impregnation with the polymer elastic body, after the impregnation, and after the raising treatment. If the seawater treatment is performed before application of the polymer elastic body, the polymer elastic body is in close contact with the ultrafine fibers, and the ultrafine fibers can be strongly held, so that the wear resistance of the sheet-like material is improved. On the other hand, when seawater removal treatment is performed after the polymer elastic body is applied, voids are generated between the polymer elastic body and the ultrafine fibers due to the sea component being desealed. In addition, the compression property of the sheet-like material is improved.

  As a method for obtaining the fiber entangled body used in the present invention, a method in which the fiber web is entangled with a needle punch or a water jet punch, a spun bond method, a melt blow method, a paper making method, or the like can be employed. Among them, a method that undergoes a treatment such as a needle punch or a water jet punch is preferably used in order to obtain an ultrafine fiber bundle as described above.

  In the needle used for the needle punching process, the number of needle barbs (cuts) is preferably 1 to 9. By using one or more needle barbs, efficient fiber entanglement becomes possible. On the other hand, fiber damage can be suppressed by using 9 or less needle barbs.

The number of punching is preferably 1000 to 6000 / cm ² . By setting the number of punching to 1000 pieces / cm ² or more, denseness can be obtained and high-precision finishing can be obtained. On the other hand, by setting the number of punching to 6000 / cm ² or less, deterioration of workability, fiber damage, and strength reduction can be prevented.

  Moreover, when performing a water jet punch process, it is a preferable aspect that water is performed in a columnar flow state. Specifically, it is a preferred embodiment that water is ejected from a nozzle having a diameter of 0.05 to 1.0 mm at a pressure of 2 to 60 MPa.

It is preferable that the apparent density of the fiber entangled body composed of the ultrafine fiber generating fiber after the needle punching process or the water jet punching process is 0.15 to 0.40 g / cm ³ . By setting the apparent density to 0.15 g / cm ³ or more, a fiber entangled body having excellent shape stability and dimensional stability can be obtained. On the other hand, when the apparent density is 0.40 g / cm ³ or less, a sufficient space for applying the elastic polymer can be maintained between the fibers.

  The fiber entangled body composed of the ultrafine fiber-generating fibers thus obtained is preferably subjected to heat shrinkage treatment with dry heat or wet heat, or both from the viewpoint of densification, and further densified. It is. It can also be compressed in the thickness direction by calendaring or the like.

  In addition, in order to obtain denseness and uniformity of the fiber distribution on the surface of the sheet-like material, the polymer elastic body is a fiber bundle of ultrafine fibers such as a nonwoven fabric in which a fiber bundle of ultrafine fibers is entangled. It is preferable that it does not exist substantially inside. If the polymer elastic body exists inside the fiber bundle, the polymer elastic body is adhered to each ultrafine fiber, so that the opening property during the buffing process is poor.

As a method for obtaining a form in which the polymer elastic body does not substantially exist inside the fiber bundle of ultrafine fibers, for example, the polymer elastic body is used as a solution,
(1) A solvent that does not dissolve the elastic component of the sea-island fiber after impregnating and solidifying the above-mentioned polymer elastic body solution into a fiber entangled body composed of ultra-fine fiber-generating sea-island fiber To dissolve and remove with
(2) A fiber entangled body composed of ultra-fine fiber-generating sea-island fibers is provided with polyvinyl alcohol having a saponification degree of preferably 80% or more to protect most of the surroundings of the sea-island fibers. A method of removing polyvinyl alcohol after dissolving and removing the sea component with a solvent that does not dissolve polyvinyl alcohol, and then impregnating and solidifying the polymer elastic body solution.
Etc. can be preferably used.

  When a polyurethane-based elastomer liquid is impregnated into a fiber entangled body and solidified, if the polyurethane-based elastomer is a solvent-based polyurethane-based elastomer, it can be coagulated by dry heat coagulation, wet coagulation or a combination thereof. it can. In the case of a water-dispersed polyurethane elastomer, the polyurethane elastomer can be coagulated by dry heat coagulation, wet heat coagulation, wet coagulation, or a combination thereof.

  When the polyurethane elastomer is solvent-based, wet coagulation is preferred in which it is immersed in water and coagulated, and when the polyurethane elastomer is water-dispersed polyurethane, wet heat coagulation is preferably used. When the polyurethane elastomer is water-dispersed, it is preferably used to exhibit heat-sensitive coagulation. In water-dispersed polyurethane elastomers, if they do not exhibit heat-sensitive coagulation, the polyurethane elastomer liquid undergoes a migration phenomenon that concentrates on the surface of the fiber entangled body during dry coagulation, and the sheet-like material containing the polyurethane elastomer is , Tend to harden. Here, the heat-sensitive coagulation property refers to the property that when the polyurethane elastomer liquid is heated, the fluidity of the polyurethane elastomer liquid decreases and solidifies when reaching a certain temperature (thermal coagulation temperature).

  The heat-sensitive coagulation temperature of the water-dispersed polyurethane elastomer is preferably 40 to 90 ° C. By setting the heat-sensitive coagulation temperature to 40 ° C. or higher, stability during storage of the polyurethane elastomer liquid is improved, and adhesion of the polyurethane elastomer to the machine during operation can be suppressed. Moreover, the migration phenomenon of the polyurethane-type elastomer in a fiber entanglement body can be suppressed by making a thermal coagulation temperature 90 degrees C or less, and it can make it unevenly distribute inside.

  In order to set the heat-sensitive coagulation temperature as described above, a heat-sensitive coagulant can be appropriately added. Examples of heat-sensitive coagulants include inorganic salts such as sodium sulfate, magnesium sulfate, calcium sulfate and calcium chloride, and radical reactions such as sodium persulfate, potassium persulfate, ammonium persulfate, azobisisobutyronitrile and benzoyl peroxide. Initiators are mentioned.

  The wet coagulation temperature is not particularly limited in the case of a solvent-based polyurethane elastomer. In the case of a water-dispersed polyurethane elastomer, it may be at least the heat-sensitive coagulation temperature of the polyurethane elastomer, and is preferably 40 to 100 ° C, for example. By setting the temperature of wet coagulation in hot water to 40 ° C. or higher, more preferably 80 ° C. or higher, the time to solidification of the polyurethane-based elastomer can be shortened to further suppress the migration phenomenon.

  The wet heat coagulation temperature may be at least the heat coagulation temperature of the water-dispersed polyurethane elastomer, and is preferably 40 to 200 ° C., for example. By setting the wet heat coagulation temperature to 40 ° C. or higher, more preferably 80 ° C. or higher, the time to solidification of the polyurethane elastomer can be shortened to further suppress the migration phenomenon. On the other hand, by setting the wet heat coagulation temperature to 200 ° C. or lower, more preferably 160 ° C. or lower, it is possible to prevent thermal degradation of the polyurethane elastomer.

  Dividing the obtained polymer elastic body-provided sheet-like material into half or several sheets in the sheet thickness direction after imparting the polymer elastic body to the fiber entangled body is a preferable aspect with excellent production efficiency. The same applies when no polymer elastic body is applied.

The sheet-like material of the present invention may have naps of ultrafine fibers on at least one surface of a sheet-like material comprising a fiber entangled body containing ultrafine fibers and a polymer elastic body of 5 % by mass or less based on the mass of the ultrafine fibers. is important.

  This napping is generally obtained by buffing. The buffing treatment here can be performed by a method of grinding and rubbing the sheet surface of a fiber entangled body such as ultrafine fiber using a sandpaper or a roll sander. In particular, the surface of the sheet can be buffed using sandpaper to form uniform and dense napping.

  By applying a lubricant such as a silicone emulsion to the sheet-like material before the raising process, the surface of the ultrafine fibers is protected and an effect of suppressing fusion is exhibited, and the fiber opening property is also improved by the lubricating effect. In addition, applying an antistatic agent before the raising treatment of the sheet-like material is a preferable embodiment in order to make it difficult for the grinding powder generated from the sheet-like material to be deposited on the sandpaper by grinding.

  Further, in order to allow uniform and dense napping to exist on the napped surface in a state where the napped coverage is high, the surface of the fiber entangled body such as a nonwoven fabric or the entire fiber entangled body is treated in a wet state with a solution such as water or chemicals. Is a preferred embodiment. By setting it in a wet state, the fine fibers are prevented from fusing with each other by buffing, and the spreadability is also increased. It is also possible to suppress fusion by protecting the fiber with the above-mentioned silicone emulsion and buffing in a dry state, but in film-forming protection, if the amount applied is not excessive so that the protective layer is thick, the fusion effect Is insufficient. In that respect, for example, water is a preferable embodiment because a considerable amount of water can be present on the surface of the ultrafine fiber even by a method of applying to the surface and can be removed by drying after the buffing treatment. From this point of view, an organic solvent can be used as the solution as long as it does not affect the substance constituting the sheet. Various methods can be combined for buffing treatment, such as buffing treatment in a dry state followed by buffing treatment in a wet state.

  The sheet-like material can be dyed depending on the application. As a method for dyeing a sheet-like material, it is preferable to use a liquid dyeing machine because the sheet-like material can be softened by simultaneously giving a stagnation effect. If the dyeing temperature of the sheet-like material is too high, the polymer elastic body may be deteriorated. On the other hand, if it is too low, the dyeing to the fiber becomes insufficient. In general, the dyeing temperature is preferably 80 to 150 ° C, more preferably 110 to 130 ° C.

  The dye can be selected according to the type of fiber constituting the sheet-like material. For example, disperse dyes can be used for polyester fibers, acidic dyes or metal-containing dyes can be used for polyamide fibers, and combinations thereof can be used.

  Moreover, it is also a preferable aspect to use a dyeing assistant when dyeing the sheet-like material. By using a dyeing assistant, the uniformity and reproducibility of dyeing can be improved. In addition, a finishing treatment using a softening agent such as silicone, an antistatic agent, a water repellent, a flame retardant, a light proofing agent, and an antibacterial agent can be performed in the same bath or after dyeing.

  The sheet-like material of the present invention includes furniture, chairs and wall materials, interior materials having a very elegant appearance as a skin material such as seats, ceilings and interiors in vehicles such as automobiles, trains and aircraft, shirts, jackets, Industry such as casual shoes, sports shoes, men's shoes and women's shoes, such as uppers, trims, bags, belts, wallets, etc. It can be suitably used as a material for use. The sheet-like material of the present invention is particularly preferably used as an abrasive cloth that is suitably used for polishing and / or cleaning.

  In the method of performing polishing using the polishing cloth of the present invention, a tape obtained by cutting the polishing cloth into a tape having a width of 30 to 50 mm is used as the polishing tape from the viewpoint of processing efficiency and stability.

  A method of polishing an aluminum alloy magnetic recording disk using the polishing tape and slurry containing free abrasive grains is suitable. As a polishing condition, a slurry in which high-hardness abrasive grains such as diamond fine particles are dispersed in an aqueous dispersion medium is preferably used. From the viewpoint of holding and dispersing the abrasive grains, the abrasive grain size suitable for the ultrafine fibers constituting the polishing cloth of the present invention is preferably 0.2 μm or less.

  Next, the sheet-like material of the present invention will be described more specifically using examples, but the present invention is not limited only to these examples. Next, the evaluation methods used in the examples and the measurement conditions will be described.

(1) Average single fiber diameter and fiber diameter CV value The average single fiber diameter was observed with a scanning electron microscope (SEM) using a cross-section of the sheet-like material cut in the thickness direction as an observation surface. The single fiber diameter of the ultrafine fiber is measured, and the standard deviation and average value are calculated using this as the population. The average value was defined as the average single fiber diameter, and the value obtained by dividing the standard deviation by the average value as a percentage (%) was defined as the fiber diameter CV value. When fibers having an average single fiber diameter of more than 5 μm are mixed, the fiber is excluded from the measurement target of the average single fiber diameter as not corresponding to the ultrafine fiber.

(2) Horizontal density and linear density CV value of the fibers arranged in the vertical direction For the linear density, the observation magnification of the sheet-like material by a scanning electron microscope (SEM) with the surface of the sheet-like material as the observation surface Take 30 images of 5000x magnification. From the photographed image, avoid a portion where a polymer elastic body such as polyurethane is exposed on the surface and no ultrafine fiber is present, or a portion where a large hole is formed by a needle punch or the like, and a reference line of 10 μm is aligned in the horizontal direction. Draw a place. Lines in the horizontal direction of the fibers arranged in the vertical direction by calculating the average value of n number 30 by measuring the number of ultra fine fibers having an acute angle of 60 ° or more intersecting with the reference line in the vertical direction. Density.
(3) Napping coverage The napping coverage of the napped surface of the sheet-like material is enlarged to an observation magnification of 40 times so that the presence of napped fibers can be seen by a scanning electron microscope (SEM) as described above, and image analysis is performed. Using software ImageJ, the ratio of the total area of the napped portions per total area of 4 mm ² was calculated and used as the napped coverage.

(4) Loss of Schiefer wear For loss of Seefer wear, 100 pieces of nylon fibers made of nylon 6 and having a diameter of 0.4 mm were cut into a length of 13 mm perpendicular to the longitudinal direction of the fiber using a Seefer wear tester. 97 bundles of 6 concentric circles in a 110 mm diameter circle (1 in the center, 6 in the 17 mm diameter circle, 13 in the 37 mm diameter circle, 19 in the 55 mm diameter circle) , Using a circular brush (9700 nylon threads) arranged in a circle with a diameter of 74 mm and 32 pieces in a circle with a diameter of 90 mm, equally spaced in each circle, and a load of 8 pounds (about 3629 g) The surface of a circular sample (diameter 45 mm) of the sheet-like material was worn under the conditions of 45 times, and the mass change of the sample before and after that was measured. The average weight loss (mg) was regarded as the Schiefer wear loss.

(5) Polishing process For the polishing process, the sheet-like material of the present invention was used as a polishing cloth, and a tape having a width of 40 mm was used. As a polishing target, a substrate made of amorphous glass manufactured by HOYA whose surface roughness was controlled to 0.2 nm or less was used. In order to polish both surfaces of the substrate at once, tapes were set on both surfaces of the substrate, and free abrasive grains in which single crystal diamond particles having a primary particle diameter of 1 to 10 nm were clustered to an average diameter of 50 nm on the surface of the polishing cloth were set to 0.00. A polishing agent containing 01% is dropped on both sides at 15 ml / min, the pressure of pressing the tape to the substrate is 1000 g, the substrate rotation speed is 400 rpm, the substrate swinging frequency is 5 Hz, and the tape running speed is 2.5 cm / min. And polished for 10 seconds.

(6) Cleaning process The cleaning process is carried out by replacing the substrate immediately after the polishing process of (5) above with a polishing agent ("CHEMICLEAN" (registered trademark) PR-122 manufactured by Sanyo Chemical Co., Ltd.) as a polishing material. Washing was performed under the same conditions as the polishing process, except that the pressing pressure was 750 g and the processing time was 30 seconds, and cleaning was performed with running water.

(7) Substrate surface roughness For substrate surface roughness, a TMS-2000 surface roughness measuring instrument manufactured by Schmitt Measurement Systems, Inc. is used in accordance with JIS B0601 (2013 edition). Then, the average roughness was measured at any 10 locations on the surface of the disk substrate sample after polishing, and the measured values at 10 locations were averaged to calculate the substrate surface roughness. The lower the value, the higher the performance. When the substrate surface roughness was 0.20 nm or less, the workability was good, and when it exceeded 0.20, the workability was poor.

(8) Number of scratches The number of scratches was determined by using a Candela 6100 optical surface analyzer as a measurement target on both surfaces of 5 substrates after polishing, that is, the total area of 10 surfaces, and using a Candela 6100 optical surface analyzer as a scratch. The number of scratches was measured, and the average value of 10 measured values was evaluated. The lower the value, the higher the performance. A scratch score of 30 or less was regarded as good workability, and a scratch score exceeding 30 was regarded as poor workability.

[Example 1]
(raw cotton)
Nylon 6 having a melting point of 220 ° C. and an MFR of 58.3 g / 10 min is used as an island component, and a copolymerized polystyrene (22 mol% 2-ethylhexyl acrylate having a melting point of 53 ° C. and an MFR of 300 g / min is copolymerized ( co-PSt) was used as the sea component. Using the sea and island components described above, using a 2000 island / hole sea-island type composite die, spinning temperature 270 ° C., island / sea mass ratio 30/70, discharge rate 1.4 g / min / hole, spinning speed 1200 m The melt spinning was performed under the conditions of / min. Next, the film was stretched 2.9 times in a liquid bath at a temperature of 85 ° C., crimped using an indentation type crimper, cut, and the average single fiber diameter was 24.0 μm, and the fiber length was A 51 mm sea-island composite fiber raw cotton was obtained.

(Nonwoven fabric made of ultrafine fiber-generating fibers)
Using the raw cotton, a laminated fiber web was formed through a card process and a cross wrapper process. Next, needle punching was performed using a needle punching machine, and a nonwoven fabric made of ultrafine fiber-generating fibers having a basis weight of 800 g / m ² and an apparent density of 0.205 g / cm ³ was produced.

(Sheet)
The nonwoven fabric composed of the above-mentioned ultrafine fiber generating fiber is subjected to hot water shrinkage at a temperature of 85 ° C., then 54% by weight of polyvinyl alcohol is added to the fiber mass, and the polystyrene as a sea component is dissolved and removed using trichlorethylene, followed by drying. And the nonwoven fabric which consists of a microfiber bundle was obtained. The polyurethane DMF solution in which the polymer diol is composed of 75% by mass of the polyether-based polymer diol and 25% by mass of the polyester-based polymer diol is 5% by mass in solid content with respect to the fiber mass. The polyurethane was coagulated with a 30% DMF aqueous solution at a liquid temperature of 35 ° C., treated with hot water at a temperature of about 85 ° C. to remove DMF and polyvinyl alcohol, and the sheet (nonwoven fabric) was dried. Then, it cut in half in the thickness direction with a half-cutting machine having an endless band knife. The sheet (nonwoven fabric) after half-cutting was wetted with water so that the dry weight was 200% by mass, and then a nap was formed on both sides using a 240 mesh sandpaper to prepare a sheet-like material. .

The obtained sheet-like material has an average single fiber diameter of ultrafine fibers of 250 nm, a fiber diameter CV value of 4.7%, an apparent density of 0.310 g / cm ³ , and a semi-finished surface on which napped hairs are formed. The linear density was 34/10 μm, the napping coverage was 90%, the weight loss of the seafer was 10.0 mg, and the surface state was elegant with an extremely soft surface touch.

  In order to confirm the effect in applications requiring wiping performance and scraping performance as a wiping cloth, CD curtain, and polishing cloth, the obtained sheet-like material is a 40 mm width tape, and the above half-finished surface is the product surface The disc was polished and cleaned. The obtained disk had a surface roughness of 0.09 nm, a scratch score of 8, and good workability. The results are shown in Table 1.

[Example 2]
(raw cotton)
A raw cotton was obtained in the same manner as in Example 1 except that polyethylene terephthalate having an intrinsic viscosity of 1.20 was used as the island component, and a sea-island composite fiber having an average single fiber diameter of 24.1 μm and a fiber length of 51 mm was obtained. It was.

(Nonwoven fabric made of ultrafine fiber-generating fibers)
In the same manner as in Example 1, a nonwoven fabric made of ultrafine fiber-generating fibers having a basis weight of 831 g / m ² and an apparent density of 0.225 g / cm ³ was produced.

(Sheet)
A sheet-like material was obtained in the same manner as in Example 1 except that the above-mentioned raw cotton was used to shrink a non-woven fabric composed of ultrafine fiber-generating fibers at a temperature of 95 ° C. with hot water. The obtained sheet-like material has an average single fiber diameter of ultrafine fibers of 250 nm, a fiber diameter CV value of 4.3%, an apparent density of 0.300 g / cm ³ , and a semi-finished surface on which napped hairs are formed. The linear density was 32/10 μm, the napping coverage was 89%, the weight loss on the siever was 14.9 mg, and the surface state was elegant with an extremely soft surface touch.

  Using the obtained sheet-like material, polishing and cleaning were performed in the same manner as in Example 1. The processed disc had a surface roughness of 0.13 nm, a scratch score of 13, and good workability. The results are shown in Table 1.

[Example 3]
(raw cotton)
Other than using 8000 island / hole sea-island type composite base, island / sea mass ratio 15/85, discharge rate 0.9g / min / hole, average single fiber diameter 15.8μm, fiber length 51mm Produced a raw cotton of sea-island type composite fiber in the same manner as in Example 1.

(Nonwoven fabric made of ultrafine fiber-generating fibers)
Using the above raw cotton, in the same manner as in Example 1, a nonwoven fabric made of ultrafine fiber generating fibers having a basis weight of 820 g / m ² and an apparent density of 0.231 g / cm ³ was produced.

(Sheet)
Using the above nonwoven fabric, a sheet-like material was obtained in the same manner as in Example 1. The obtained sheet-like material has an average single fiber diameter of ultrafine fibers of 60 nm, a fiber diameter CV value of 8.3%, an apparent density of 0.303 g / cm ³ , and a semi-finished surface on which napped hairs are formed. The linear density was 122 pieces / 10 μm, the napping coverage was 87%, and the weight loss of the seafer was 11.9 mg, which was an elegant surface state with a very soft surface touch.

  Using the obtained sheet-like material, it was polished and washed by the same method as in Example 1. The processed disk had a surface roughness of 0.12 m, a scratch score of 10, and good workability. The results are shown in Table 1.

[Example 4]
(raw cotton)
A sea-island composite fiber raw cotton was obtained in the same manner as in Example 1 except that polyethylene terephthalate copolymerized with 8 mol% of sodium 5-sulfoisophthalate was used as the sea component.

(Nonwoven fabric made of ultrafine fiber-generating fibers)
Using the above raw cotton, a nonwoven fabric made of ultrafine fiber-generating fibers having a basis weight of 831 g / m ² and an apparent density of 0.225 g / cm ³ was produced in the same manner as in Example 1.

(Sheet)
A non-woven fabric composed of the above-mentioned ultrafine fiber-generating fibers is subjected to hot water shrinkage at a temperature of 85 ° C., and then a polyvinyl alcohol having a saponification degree of 99% and a polymerization degree of 1400 (NM-14 manufactured by Nippon Synthetic Chemical Co., Ltd.) Was added to the nonwoven fabric fiber mass in an amount of 54% by mass, immersed in a 10 g / liter sodium hydroxide aqueous solution heated to a temperature of 95 ° C., and treated for 30 minutes to remove the sea component of the sea-island composite fiber. A nonwoven fabric was obtained. In the nonwoven fabric thus obtained, a water-dispersed polyurethane comprising a polymer diol of 75% by mass of a polyether-based polymer diol and 25% by mass of a polyester-based polymer diol is 5% by solid content with respect to the fiber mass of the nonwoven fabric. %, Dried and solidified, treated with hot water at a temperature of about 95 ° C. to remove polyvinyl alcohol, and the sheet was dried.

Then, it cut in half in the thickness direction with a half-cutting machine having an endless band knife. The sheet after the half-cutting was wetted with water so as to be 200% by mass with respect to the dry mass, and then a nap was formed on both sides using a 240 mesh sandpaper to prepare a sheet. The obtained sheet-like material has an average single fiber diameter of ultrafine fibers of 250 nm, a fiber diameter CV value of 6.5%, an apparent density of 0.310 g / cm ³ , and a half-cut surface on which napped hairs are formed. The linear density was 30/10 μm, the napping coverage was 83%, the weight loss of the seafer was 21.5 mg, and the surface state was elegant with an extremely soft surface touch.

  The obtained sheet-like material was made into a 40 mm width tape, and the above-mentioned semi-finished surface was polished and washed, and the resulting disk had a surface roughness of 0.19 nm and a scratch score of 25. The workability was good. The results are shown in Table 1.

[Example 5]
(raw cotton)
A sea-island composite fiber raw cotton was obtained in the same manner as in Example 1 except that a 1000 island / hole sea-island type composite die was used and the discharge rate was 0.9 g / min / hole.

(Nonwoven fabric made of ultrafine fiber-generating fibers)
Using the raw cotton, in the same manner as in Example 1, a nonwoven fabric made of ultrafine fiber generating fibers having a basis weight of 770 g / m ² and an apparent density of 0.207 g / cm ³ was produced.

(Sheet)
Using the above nonwoven fabric, a sheet-like material was obtained in the same manner as in Example 1. The obtained sheet-like product has an average single fiber diameter of ultrafine fibers of 400 nm, a fiber diameter CV value of 4.2%, an apparent density of 0.295 g / cm ³ , and a semi-finished surface on which napped hairs are formed. The linear density was 22/10 μm, the napping coverage was 87%, the weight loss of the seafer was 8.0 mg, and the surface state was elegant with an extremely soft surface touch.

  Using the obtained sheet-like material, it was polished and washed by the same method as in Example 1. The processed disk had a surface roughness of 0.15 m, a scratch score of 16, and good workability. The results are shown in Table 1.

[Example 6]
(raw cotton)
A sea island type composite fiber raw cotton was obtained in the same manner as in Example 1 except that a 400 island / hole sea island type composite die was used and the average single fiber diameter was 29.7 μm and the fiber length was 51 mm. .

(Nonwoven fabric made of ultrafine fiber-generating fibers)
Using the raw cotton, in the same manner as in Example 1, a nonwoven fabric made of ultrafine fiber generating fibers having a basis weight of 800 g / m ² and an apparent density of 0.217 g / cm ³ was produced.

(Sheet)
Using the above nonwoven fabric, a sheet-like material was obtained in the same manner as in Example 1. The obtained sheet-like material has an average single fiber diameter of ultrafine fibers of 750 nm, a fiber diameter CV value of 4.1%, an apparent density of 0.313 g / cm ³ , and a semi-finished surface on which napped hairs are formed. The line density was 14/10 μm, the napping coverage was 85%, and the loss of siever wear was 18.7 mg, which was an elegant surface state with a very soft surface touch.

  Using the obtained sheet-like material, it was polished and washed by the same method as in Example 1. The processed disc had a surface roughness of 0.19 m, a scratch score of 25, and good workability. The results are shown in Table 1.

[ Reference Example 1 ]
(raw cotton)
In the same manner as in Example 1, a raw cotton of sea-island type composite fiber was obtained.

(Nonwoven fabric made of ultrafine fiber-generating fibers)
Using the above raw cotton, a nonwoven fabric made of ultrafine fiber-generating fibers was produced in the same manner as in Example 1.

(Sheet)
A sheet-like material was obtained in the same manner as in Example 1 except that the above-described nonwoven fabric was used and the polyurethane to be imparted was imparted so that the solid content was 12% by mass with respect to the fiber mass of the nonwoven fabric. The obtained sheet-like material has an average single fiber diameter of ultrafine fibers of 250 nm, a fiber diameter CV value of 4.6%, an apparent density of 0.323 g / cm ³ , and a semi-finished surface on which napped hairs are formed. The linear density was 32/10 μm, the napping coverage was 81%, the weight loss of the siever was 18.0 mg, and the surface state was elegant with an extremely soft surface touch.

  Using the obtained sheet-like material, it was polished and washed by the same method as in Example 1. The processed disc had a surface roughness of 0.19 m, a scratch score of 26, and good workability. The results are shown in Table 1.

[Example 8]
(raw cotton)
In the same manner as in Example 1, a raw cotton of sea-island type composite fiber was obtained.

(Nonwoven fabric made of ultrafine fiber-generating fibers)
Using the above raw cotton, a nonwoven fabric made of ultrafine fiber-generating fibers was produced in the same manner as in Example 1.

(Sheet)
After the nonwoven fabric composed of the above-mentioned ultrafine fiber generating fiber is subjected to hot water shrinkage at a temperature of 85 ° C., 54% by mass of polyvinyl alcohol is added to the fiber mass of the nonwoven fabric, and the sea component polystyrene is dissolved and removed using trichlorethylene. Thereafter, it was dried to obtain a non-woven fabric composed of ultrafine fiber bundles. The nonwoven fabric thus obtained was treated with hot water at a temperature of about 85 ° C., polyvinyl alcohol was removed, and the sheet was dried. The obtained sheet was wetted with water so as to be 200% by mass with respect to the dry mass, and then a nap was formed on both sides using a 240 mesh sandpaper to prepare a sheet. The obtained sheet-like material has an average single fiber diameter of ultrafine fibers of 250 nm, a linear density of 36 fibers / 10 μm, a fiber diameter CV value of 4.8%, a napped coverage ratio of 94%, and a seafer wear. The weight loss was 9.5 mg, the apparent density was 0.285 g / cm ³ , and the surface state was elegant with a very soft surface touch.

  Using the obtained sheet-like material, it was polished and washed by the same method as in Example 1. The processed disc had a surface roughness of 0.10 m, a scratch score of 7, and good workability. The results are shown in Table 1.

[Comparative Example 1]
(raw cotton)
A sea-island-type composite fiber raw material is made in the same manner as in Example 1 except that an average number of single fibers is 28.7 μm and the fiber length is 51 mm using a sea-island type composite base having 200 islands / hole. Obtained.

(Nonwoven fabric made of ultrafine fiber-generating fibers)
Using the raw cotton, in the same manner as in Example 1, a nonwoven fabric made of ultrafine fiber generating fibers having a basis weight of 760 g / m ² and an apparent density of 0.230 g / cm ³ was produced.

(Sheet)
Using the above nonwoven fabric, a sheet-like material was obtained in the same manner as in Example 1. The obtained sheet-like product has an average single fiber diameter of ultrafine fibers of 1000 nm, a fiber diameter CV value of 2.2%, an apparent density of 0.321 g / cm ³ , and a semi-finished surface on which napped hairs are formed. The linear density was 7/10 μm, the napping coverage was 81%, the seafer abrasion loss was 26.0 mg, and it was an elegant surface state with a soft surface touch, but the density was inferior.

  Using the obtained sheet-like material, it was polished and washed by the same method as in Example 1. The processed disk had a surface roughness of 0.28 m, a scratch score of 39, and a high scratch score. The results are shown in Table 1.

[Comparative Example 2]
(raw cotton)
In the same manner as in Example 1, a raw cotton of sea-island type composite fiber was obtained.

(Nonwoven fabric made of ultrafine fiber-generating fibers)
Using the above raw cotton, a nonwoven fabric made of ultrafine fiber-generating fibers was produced in the same manner as in Example 1.

(Sheet)
A sheet-like material was obtained in the same manner as in Example 1 except that the above-mentioned nonwoven fabric was used and the polyurethane to be imparted was imparted so that the solid content was 18% by mass with respect to the fiber mass of the nonwoven fabric. The obtained sheet-like material has an average single fiber diameter of ultrafine fibers of 250 nm, a fiber diameter CV value of 5.0%, an apparent density of 0.333 g / cm ³ , and a semi-finished surface on which napped hairs are formed. The linear density was 30/10 μm, the napping coverage was 75%, and the seafer abrasion loss was 32.0 mg. As for wear, the sheer wear loss was increased because the ultrafine fiber bundle held by the polyurethane fell off. The sheet-like material had a soft surface touch, but the density was inferior.

  Using the obtained sheet-like material, it was polished and washed by the same method as in Example 1. The processed disk had a surface roughness of 0.21 m and a scratch score of 31. The results are shown in Table 1.

[Comparative Example 3]
(raw cotton)
Nylon 6 having a melting point of 220 ° C. and an MFR of 58.3 g / 10 min is used as an island component, and a copolymerized polystyrene (22 mol% 2-ethylhexyl acrylate having a melting point of 53 ° C. and an MFR of 300 g / min is copolymerized ( Co-PSt) was used as a sea component and discharged from a melt composite spinning die at a mass ratio of 30:70 to form a raw cotton made of sea-island cross-section composite fibers.

(Nonwoven fabric made of ultrafine fiber-generating fibers)
In the same manner as in Example 1, a nonwoven fabric made of ultrafine fiber generating fibers having a basis weight of 760 g / m ² and an apparent density of 0.223 g / cm ³ was produced.

(Sheet)
Using the above raw cotton, a sheet-like material was obtained in the same manner as in Example 1. The obtained sheet-like material has an average single fiber diameter of ultrafine fibers of 250 nm, a fiber diameter CV value of 28.6%, an apparent density of 0.311 g / cm ³ , and a semi-finished surface on which napped hairs are formed. The linear density was 11 pieces / 10 μm, the napping coverage was 80%, and the weight loss on the siever was 16.1 mg. The sheet-like material was rough in touch, and had an appearance quality inferior in denseness and uniformity.

  Using the obtained sheet-like material, it was polished and washed by the same method as in Example 1. The processed disk had a surface roughness of 0.24 nm, a scratch score of 45, and a high scratch score. The results are shown in Table 1.

[Comparative Example 4]
(raw cotton)
In the same manner as in Example 1, a raw cotton of sea-island type composite fiber was obtained.

(Nonwoven fabric made of ultrafine fiber-generating fibers)
Using the above raw cotton, a nonwoven fabric made of ultrafine fiber-generating fibers was produced in the same manner as in Example 1.

(Sheet)
Using the non-woven fabric, a half-cut sheet was obtained in the same manner as in Example 1. The sheet after half-cutting was made dry using 240 mesh sandpaper to form napped on both sides to produce a sheet-like material. The resulting sheet-like material has an average fiber diameter of ultrafine fibers of 250 nm, a fiber diameter CV value of 4.8%, an apparent density of 0.323 g / cm ³ , The linear density was 3/10 μm, the napping coverage was 69%, and the loss of Seefer abrasion was 30.5 mg. The ultrafine fibers were partly fused with each other, and sufficient napping was not obtained, resulting in a rough surface touch.

  Using the obtained sheet-like material, it was polished and washed by the same method as in Example 1. The processed disk had a surface roughness of 0.35 m and a scratch score of 48. The results are shown in Table 1.

[Comparative Example 5]
(raw cotton)
Other than using a sea-island type composite base of 10,000 islands / hole, an island / sea mass ratio of 10/90, a discharge rate of 0.7 g / min / hole, an average single fiber diameter of 17.2 μm, and a fiber length of 51 mm Produced a raw cotton of sea-island type composite fiber in the same manner as in Example 1.

(Nonwoven fabric made of ultrafine fiber-generating fibers)
Using the above raw cotton, in the same manner as in Example 1, a nonwoven fabric made of ultrafine fiber generating fibers having a basis weight of 820 g / m ² and an apparent density of 0.231 g / cm ³ was produced.

(Sheet)
Using the above nonwoven fabric, a sheet-like material was obtained in the same manner as in Example 1. The obtained sheet-like material has an average single fiber diameter of ultrafine fibers of 30 nm, a fiber diameter CV value of 12.2%, an apparent density of 0.303 g / cm ³ , and a semi-finished surface on which napped hairs are formed. The linear density was 34/10 μm, the napping coverage was 67%, and the loss of wear on the seafer was 31.1 mg. The fiber diameter CV value was low, the ultrafine fibers were partially fused together, and sufficient napping was not obtained, resulting in a rough surface touch.

  Using the obtained sheet-like material, it was polished and washed by the same method as in Example 1. The processed disk had a surface roughness of 0.35 m and a scratch score of 48. The results are shown in Table 1.

  As described above, in Example 1, an elegant sheet-like material was obtained with an extremely soft surface touch, which was suitable as an abrasive tape. On the other hand, in Comparative Example 1, since the average single fiber diameter was large and the linear density was low, the sheet was inferior in density, and the scratch score was high when used as an abrasive tape. In Comparative Example 2, since the amount of the polymer elastic body is large, the napping coverage is small and the sheet is inferior in density, and the wear loss is increased by the weight loss of the polymer elastic body. There were many scratches. In Comparative Example 3, since the fiber diameter CV value was large, the sheet-like material was rough in touch, had an appearance quality inferior in density and uniformity, and was not suitable as a polishing tape. In Comparative Example 4, since the buffing treatment in the wet state as in Example 1 is not performed, such as the suppression of the fusion of the ultrafine fibers and the improvement of the spreadability are not performed, the fusion of the fibers and the failure of the spread occur. The density of the sheet-like material is low, the touch is rough, the appearance quality is inferior in the denseness and uniformity, and it is not suitable as a polishing tape. In Comparative Example 5, since the average single fiber diameter is too small, the fiber diameter CV value is high, the spreadability is poor, and the sheet-like material is rough in appearance, inferior in the fineness and uniformity, and the polishing tape It was not suitable as.

Claims (7)

A sheet-like material comprising a fiber entanglement mainly composed of ultrafine fibers having an average single fiber diameter of 50 to 800 nm, and the amount of the polymer elastic body with respect to the mass of the ultrafine fibers is 5 % by mass or less, One side or both sides of the sheet-like material is constituted by raised surfaces, and the linear density of fibers arranged in the vertical direction on at least one side of the raised surfaces is 12/10 μm width to 150/10 μm width. Oh I, piloerection coverage of the surface transversely of the linear density of the fibers arranged in the longitudinal direction is 12/10 [mu] m width and 150 present / 10 [mu] m width and wherein 70% to 99% der Rukoto Sheet material. Sheet of claim 1 Symbol placement average single fiber diameter of the ultrafine fibers is 50 to 450 nm. The sheet-like material according to claim 1 or 2, wherein the ultrafine fiber has a single fiber diameter CV value of 0.1 to 10%. The sheet-like material according to any one of claims 1 to 3 , wherein the sheet-like material does not contain a polymer elastic body. To any one of claims 1 to 4, characterized in that Schiefer abrasion loss of the surface transverse direction of the linear density of the fibers arranged in the longitudinal direction is 12/10 [mu] m width and 150 present / 10 [mu] m width is less than 30mg The sheet-like material described. The sheet-like material according to any one of claims 1 to 5 , which is used for an abrasive cloth. A sheet-like material comprising a fiber entanglement mainly composed of ultrafine fibers having an average single fiber diameter of 50 to 800 nm, wherein the amount of the polymer elastic body with respect to the mass of the ultrafine fibers is 5 % by mass or less. The method for producing a sheet-like product according to any one of claims 1 to 6 , wherein the sheet is buffed with a solution so that the surface or the entire sheet is in a wet state.