JP4649784B2 - Method for producing napped leather-like sheet - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing napped leather-like sheet-like material having excellent quality, durability, and processability. More specifically, the present invention relates to a method for producing a suede-like napped sheet-like material having an elegant appearance, an appropriate texture and durability, and having excellent stability during grinding.
[0002]
[Prior art]
Nude leather-like sheet material, especially suede-like artificial leather mainly composed of ultrafine fibers with a fineness of 0.3 dtex or less and polyurethane, is not only superior in surface touch and flexibility, but also in uniformity and color fastness not found in natural leather Has the flexibility of texture and texture.
[0003]
In order to form napping of such a leather-like sheet material, it is a common practice to grind the surface of the sheet material made of ultrafine fibers and polyurethane. As such grinding treatment, sandpaper or abrasive powder is applied to the surface. A method of rubbing against the sheet surface while rotating a roll or the like having high speed is common.
[0004]
In addition, since a large amount of grinding powder is generated when grinding the surface of the sheet-like material, a method of installing an air duct near the grinding part and removing the grinding powder in order to remove this is generally used. . Furthermore, in order to increase dust removal efficiency, a method may be used in which an air nozzle is provided at a position close to the air duct, and air is ejected from the air nozzle to blow off grinding powder adhering to the sheet surface, sandpaper or the like.
[0005]
However, even if such a method is used, the removal of the grinding powder is not always sufficient, and when grinding is performed a plurality of times, the napped state differs depending on the grinding powder remaining on the sheet surface. However, there was a problem that it was uneven and lacked in luxury. Also, if continuous machining is performed for a long time, grinding powder accumulates on the air nozzle, and some or all of the air blowing holes opened in the air nozzle are clogged with grinding powder, so that grinding powder removal is further insufficient. Thus, there is a problem that the surface quality becomes nonuniform due to the grinding powder adhering to the sheet surface or sandpaper. Regarding grinding powder accumulated on the air nozzle, it is possible to avoid the above problem by cleaning the periphery of the air nozzle, but since it is necessary to clean frequently, processing takes time and manufacturing costs increase. There was a problem.
[0006]
In addition, when trying to increase the durability of leather-like sheet-like materials, it is necessary to use a polycarbonate-based or polyester-based polyurethane having excellent durability in place of the polyether-based polyurethane that has been widely used conventionally. However, when such polyurethane is used, there is a problem that grinding powder is particularly difficult to remove and the processability of the leather-like sheet is very low.
[0007]
[Problems to be solved by the invention]
  Therefore, in view of the problems in the prior art as described above, the object of the present invention is to improve durability and quality.(In particular, as will be described later, the surface has a long raised surface, has an appropriate gloss, and has a fine appearance with few dyeing spots when dyeing is performed.), Grinding processing stability(Especially, as described above, grinding stability for solving the problems caused by the accumulation of grinding powder on the air nozzle)Another object of the present invention is to provide a method for producing a napped-leather-like sheet-like sheet having excellent properties.
[0008]
[Means for Solving the Problems]
  In order to solve the above-mentioned problem, the method for producing a napped-toned leather-like sheet according to the present invention comprises an ultrafine fiber andComprising polycarbonate diol, organic diisocyanate and low molecular diolAntistatic agent for polyurethane sheetAnd silicone lubricantAnd then grinding.
[0010]
In these methods according to the present invention, it is preferable to apply a grinding treatment after applying an antistatic agent so that the frictional voltage measured by the method described in JIS L1094B is in the range of −500 to + 5000V.
[0011]
  In the method for producing a napped leather-like sheet according to the present invention, the content of the polyether contained in the polymer diol constituting the polyurethane is preferably 30% by weight or less.. TheFurthermore, the polyurethane preferably contains a polycarbonate diol, a polyester diol, an organic diisocyanate and a low molecular diol.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail together with preferred embodiments.
Upon completion of the present invention, the above-mentioned problems, i.e., a method for producing a leather-like sheet excellent in durability, quality, and processing stability, are intensively studied, and an antistatic agent is imparted to the sheet-like material composed of ultrafine fibers and polyurethane. After that, when grinding was applied, this problem was solved all at once, and surprisingly, a napped leather-like sheet-like material having moderate gloss and napping and few dyeing spots when dyeing was obtained. I found out that
[0013]
The fiber material constituting the napped leather-like sheet-like material in the present invention is not particularly limited, but polyesters such as polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate and copolymers thereof, nylon 6, nylon 6, 6 and co-polymers. Polyamides such as polymerized nylon or a mixture thereof can be used.
[0014]
Such fibers are preferably mainly composed of fibers of 0.3 dtex or less from the viewpoint of flexibility and quality, but even if fibers thicker than 0.3 dtex are mixed within a range not impairing the object of the present invention. Good. The cross-sectional shape of the ultrafine fiber is not particularly limited, and may be a round cross section or a so-called irregular cross section such as a triangle or a cross. Such fibers may exist in the form of single fibers or in the form of fiber bundles, or may exist in a state where single fibers and fiber bundles are appropriately mixed. .
[0015]
As a form at the time of making the ultrafine fiber in the present invention into a sheet, a woven fabric, a knitted fabric, a nonwoven fabric, and a composite of them can be adopted. As such a woven fabric, a normal plain weave or twill weave can be used, and as a knitted fabric, warp knitting or tubular knitting can be used. Moreover, as a nonwoven fabric, although a short fiber nonwoven fabric, a long fiber nonwoven fabric, etc. may be used, a short fiber nonwoven fabric is preferably used from a viewpoint of texture and quality.
[0016]
The polyurethane used in the present invention is not particularly limited as long as it satisfies the target physical properties, quality, texture and durability, but non-polyether polyurethane when high durability, particularly light resistance, is to be obtained. Is preferably used. The term “non-polyether polyurethane” as used herein means that the content of the polyether contained in the polymer diol used as a raw material for polyurethane is 30% by weight or less, preferably 15% by weight or less, more preferably 5% by weight or less. Say.
[0017]
As such a polymer diol, it is preferable to mainly use a polycarbonate diol from the viewpoint of durability, but in order to obtain a leather-like sheet-like material having more flexibility, it is more preferable to use a mixture of a polycarbonate diol and a polyester diol. preferable. At this time, the mixing ratio of the polycarbonate diol and the polyester diol is preferably 100/0 to 20/80, more preferably 75/25 to 30/70 in terms of weight ratio. If the weight ratio of the polyester diol exceeds 80%, the obtained leather-like sheet is inferior in durability, which is not preferable.
[0018]
The polycarbonate diol used in the present invention can be obtained, for example, by reacting a carbonate compound and a diol. As the carbonate compound, dimethyl carbonate, diphenyl carbonate, ethylene carbonate and the like can be used. Examples of the diol include ethylene glycol, propylene glycol, butanediol, pentanediol, neopentyl glycol, methylpentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, dodecanediol, and other aliphatic diols, cyclohexanediol, etc. One or a mixture of two or more aromatic diols such as alicyclic diol and xylylenediol can be used.
[0019]
The polyester diol used in the present invention is obtained by condensing an aliphatic diol and an aliphatic carboxylic acid. In such aliphatic diols and aliphatic carboxylic acids, those having 2 to 10 carbon atoms are preferably used because if they have a carbon number greater than 12, they will be inferior in cold resistance and flexibility. Moreover, when importance is attached to flexibility, it is preferable to appropriately provide a branch such as a methyl group or an ethyl group.
[0020]
  The molecular weights of the polycarbonate diol and polyester diol are not particularly limited, but those having a molecular weight of usually 500 or more and 5000 or less are preferred, and those having a molecular weight of 1000 or more and 4000 or less can be used. If it is less than 500, the flexibility of the leather-like sheet is lost, or the texture is liable to be lowered, which is not preferable. On the other hand, if the molecular weight exceeds 5000, it is not preferable because the concentration of urethane groups decreases or it becomes difficult to obtain a sheet-like material having a good balance of texture, flexibility and durability. Thus, the polyurethane in the present invention contains polycarbonate diol, organic diisocyanate and low molecular diol.And even moreThose containing polycarbonate diol, polyester diol, organic diisocyanate and low molecular weight diol are preferred.
[0021]
There is no restriction | limiting in particular as diisocyanate combined with these diol in a polyurethane, The thing generally used for the synthesis | combination of a polyurethane can be selected suitably, and can be used. For example, when heat resistance is important, aromatic diisocyanate such as 4,4′-diphenylmethane diisocyanate can be used, and when it is desired to suppress yellowing due to NOx or light, isophorone diisocyanate or 4,4′- Alicyclic diisocyanates such as dicyclohexylmethane diisocyanate and aliphatic diisocyanates can be used. Further, a plurality of these may be mixed and used according to the purpose.
[0022]
  As a polyurethane chain extender used in the present invention,Low molecular diolCan be used. Examples of these include ethylene glycol, propylene glycol, 1,6-hexanediol, etc.TheCan be mentioned. Moreover, these chain extenders can also be mixed and used suitably.
[0023]
As the above-mentioned diisocyanate and chain extender, 4,4'-diphenylmethane diisocyanate and an aliphatic diol having 2 to 8 carbon atoms, particularly ethylene glycol, are used, and the polyurethane has outstanding durability and flexibility. Is preferable.
[0024]
The method for producing the polyurethane in the present invention is not particularly limited, and a so-called prepolymer method in which a polymer diol and a diisocyanate are reacted to form a prepolymer and then reacted with a chain extender may be used. Alternatively, a so-called one-shot method in which a polymer diol, diisocyanate, and a chain extender are reacted simultaneously may be used.
[0025]
Moreover, an organic tin compound, an organic titanium compound, a tertiary amine, etc. can also be added as a catalyst of reaction.
[0026]
As the polyurethane solvent in the present invention, for example, N, N′-dimethylformamide (DMF), dimethylacetamide, or the like can be used. Further, other solvents and water can be added as long as the solubility of the polyurethane is not hindered. In addition, for the purpose of adjusting the solidification structure of the polyurethane, a solidification regulator such as a higher alcohol or a surfactant can be added. Furthermore, pigments, ultraviolet absorbers, antioxidants, hydrolysis inhibitors and the like may be added depending on the purpose.
[0027]
A wet coagulation method is preferably used as the polyurethane coagulation method in the present invention. The wet coagulation conditions are not particularly limited, and a method usually performed in artificial leather production can be applied. For example, a sheet made of ultrafine fibers is impregnated in a solution having a polyurethane concentration of 5 to 30%, and substantially DMF. It can be solidified by adding it into an aqueous solution having a mixing ratio of 60/40 to 0/100 and a temperature of 20 to 70 ° C. Alternatively, polyurethane can be coagulated by sequentially adding it into two or more aqueous solutions having different mixing ratios and temperatures of DMF and water.
[0028]
In the present invention, the composition ratio of polyurethane and ultrafine fiber in the leather-like sheet is adjusted by the polyurethane concentration at the time of impregnation, the squeezing condition after the impregnation, and preferably in the range of 1: 9 to 4: 6. . When the ratio of polyurethane to ultrafine fibers is 1: 9 or less, the amount of polyurethane is too small, which is not preferable because of poor physical properties and durability. When the ratio is 4: 6 or more, the texture becomes hard, which is not preferable.
[0029]
Further, the density of the leather-like sheet in the present invention is 0.2 to 0.6 g / cm.^ThreeIs preferably in the range of 0.3 to 0.5 g / cm.^ThreeMore preferably, it is in the range. Density is 0.2g / cm^ThreeThe following cases tend to be inferior in physical properties and durability, 0.6 g / cm^ThreeThe above case is not preferable because the texture tends to be hard.
[0030]
In addition, the method according to the present invention is characterized in that a grinding treatment is performed after applying an antistatic agent. Such an antistatic agent is largely classified into a low molecular type and a high molecular type, and is not particularly limited as long as it satisfies the object of the present invention.
[0031]
For example, as a low molecular weight type antistatic agent, nonionic glycerin fatty acid ester, higher alcohol EO adduct, polyethylene glycol fatty acid ester, anionic alkyl sulfonate, higher alcohol sulfate, higher alcohol EO adduct A sulfate ester salt, a higher alcohol phosphate ester salt, a higher alcohol EO adduct phosphate ester salt, a cationic tetraalkylammonium salt, or an amphoteric alkylbetaine can be used. Examples of the polymer antistatic agent include nonionic polyether, polyether polyesteramide, polyetheramideimide, methoxypolyethylene glycol (meth) acrylate copolymer, anionic polystyrene sulfonate, and the like. A cationic quaternary ammonium base-containing (meth) acrylate copolymer, a quaternary ammonium base-containing maleimide copolymer, or the like can be used.
[0032]
The amount of the antistatic agent applied is preferably 0.03 to 3%, more preferably 0.05 to 1% based on the sheet weight before grinding, although it depends on the type of antistatic agent. It is good to do. If the applied amount is 0.03% or less, the intended effect of the present invention cannot be obtained sufficiently, and if it is more than 3%, the effect is hardly changed even if the applied amount is increased, and only the cost is not preferable. .
[0033]
Moreover, such an antistatic agent may be used alone, or two or more kinds of antistatic agents may be used in combination. As a method of applying a combination of two or more kinds of antistatic agents, one antistatic agent may be applied and then the other antistatic agent may be applied, or a plurality of antistatic agents may be added within a range in which aggregation and precipitation do not occur. You may mix and provide an agent.
[0034]
A method for applying such an antistatic agent is not particularly limited, but a method of spraying with a spray, a method of applying with a coater, a method of impregnating with a solution containing an antistatic agent and then squeezing by nip with a roll, etc. Can be used.
[0035]
Further, as the characteristics of the sheet-like material after the application of the antistatic agent, the frictional voltage measured by the method described in JIS L1094 B is preferably in the range of −500 to +5000 V, more preferably 0 to It is within the range of + 3000V. If the frictional voltage is outside the range of −500 to +5000 V, the grinding powder tends to adhere to the sheet surface, sandpaper, air nozzle, etc., and the effects of the present invention cannot be obtained sufficiently, which is not preferable.
[0036]
  In the present invention,IsGrinding after applying antistatic agent and silicone lubricantTheCombining such a silicone lubricant and antistatic agent, the surface has a long raised surface, has an appropriate gloss, and has an elegant appearance with few dyeing spots when dyed.Excellent grade withA napped leather-like sheet-like material can be obtained. As such a silicone-based lubricant, dimethylpolysiloxane, methylhydrogenpolysiloxane, amino-modified silicone, carboxyl-modified silicone and the like can be used.
[0037]
The method for applying such a silicone lubricant is not particularly limited, and a method of spraying with a spray, a method of applying with a coater, a method of impregnating with a solution containing a silicone lubricant and nipping with a roll, etc. are used. Can do. Further, either one of the antistatic agent and the silicone-based lubricant may be applied first, and then the other may be applied, or these may be mixed and applied simultaneously. Moreover, you may add other chemical | medical agents, such as a coagulation inhibitor, in the range which does not impair the effect of this invention.
[0038]
The amount of silicone lubricant applied is preferably 0.03 to 1% by weight, more preferably 0.05 to 0.3% by weight, based on the weight of the sheet before grinding. When the application amount of the silicone-based lubricant is 0.03% by weight or less, it is not preferable because napping is short and the surface quality tends to be inferior. When the applied amount is 1% by weight or more, the coefficient of friction of the sheet surface becomes too small, so that the sheet becomes easy to meander during the grinding process, and the silicone-based lubricant is transferred to the grinding machine, resulting in poor workability. Therefore, it is not preferable.
[0039]
In addition, an important factor that affects the surface quality of the leather-like sheet material is the coefficient of friction between the sheet and the sandpaper during the grinding process. By reducing the coefficient of friction between the sheet and sandpaper, polyurethane is preferentially ground over ultrafine fibers, resulting in a leather-like sheet with long nap and moderate gloss. Not only the lubricants but also antistatic agents have the function of reducing the coefficient of friction between the sheet and the sandpaper, and it is believed that the application of antistatic agents will provide a napped leather-like sheet with superior surface quality. ing.
[0040]
In addition, the details of the relationship between the antistatic agent and the dyeing spots are unclear, but the antistatic agent remaining in a trace amount in the sheet moderately inhibits the migration of the dye to the ultrafine fibers, resulting in good dyeing spots. It is considered that a quality leather-like sheet is obtained.
[0041]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. In addition, the meaning of the symbol used in an Example and a comparative example is as follows.
PHC: Polyhexamethylene carbonate diol
PNPA: Polyneopentyl adipate diol
MDI: 4,4'-diphenylmethane diisocyanate
EG: Ethylene glycol
DMF: N, N'-dimethylformamide
[0042]
Reference example
  Island component is polyethylene terephthalate, sea component is polystyrene, island / sea ratio = 55/45% by weight, number of islands is 36 islands, composite fiber fineness is about 3dtex, cut length is about 51mm, and crimped number is 14 mountains / inch. A web is made through the process of card and cross wrapping using the raw cotton and then needle punched to give a basis weight of 610 g / m²The felt was made.
[0043]
The felt was impregnated with a polyvinyl alcohol solution having a liquid temperature of about 95 ° C. and a concentration of about 12%, and squeezed with a nip roll to give 30% polyvinyl alcohol in a solid content to the island components, followed by drying. Thereafter, sea components were removed with trichlorethylene at about 30 ° C. to obtain a fiber sheet-like product composed of ultrafine fibers having a single fiber fineness of about 0.04 dtex.
[0044]
Separately, PHC having a number average molecular weight of 2000 and PNPA having a number average molecular weight of 2000 were mixed at a weight ratio of 70:30, and DMF, EG and MDI were added thereto and reacted for about 15 hours to obtain a polyurethane solution. The polyurethane solution was diluted with DMF so that the solid content concentration was 9.5% by weight.
[0045]
The polyurethane solution was impregnated with the above fiber sheet and squeezed with a nip roll, and then the polyurethane was coagulated in a 30% DMF aqueous solution at a liquid temperature of 35 ° C., and DMF and polyvinyl alcohol were removed with hot water at about 85 ° C. . This was impregnated with an aqueous solution of a nonionic antistatic agent (“Elenite” 139; manufactured by Takamatsu Yushi Co., Ltd.), squeezed with a nip roll, and dried. At this time, the amount of nonionic antistatic agent applied was 0.10%. In addition, the value when the frictional voltage of this sheet-like material was measured by the JIS L1094 B method under the conditions of an air temperature of 20 ° C. and a humidity of 40% was + 20V.
[0046]
The surface of the sheet was ground with sandpaper. The grinding treatment was performed four times in succession, and the grinding powder adhering to the sheet surface, sandpaper, etc. was blown off with an air nozzle, and this was removed by suction from the air duct. Even after the sheet length of 5000 m was continuously processed, the amount of grinding powder deposited on the sheet surface, air nozzle, air duct, etc. was small, and the grinding process could be performed stably. Further, the amount of grinding powder adhering to the sandpaper after the grinding treatment was small, and there was no problem at all for long-time continuous processing.
[0047]
The sheet-like material thus obtained is dyed with a disperse dye and has a density of 0.320 g / cm.^ThreeOf napping leather-like sheet was obtained. The napped leather-like sheet-like material from which this fibrous material was obtained had uniform napping and an appropriate texture.
[0048]
Example1
  Reference exampleIn the same manner as above, a fiber sheet-like product composed of ultrafine fibers having a single fiber fineness of about 0.04 dtex was obtained.
[0049]
  Reference exampleUse the same polyurethane solution asReference exampleIn the same manner as above, the fiber sheet was impregnated with the polyurethane and solidified, and then DMF and polyvinyl alcohol were removed.
[0050]
This was impregnated with a mixed aqueous dispersion of a nonionic antistatic agent (“Ellenite” 139; manufactured by Takamatsu Yushi Co., Ltd.) and a silicone-based lubricant (SH7036; manufactured by Toray Dow Corning Silicone Co., Ltd.), and squeezed with a nip roll. After the liquid, it was dried. At this time, the amounts of the nonionic antistatic agent and the silicone lubricant were 0.10% and 0.15%, respectively. In addition, the value when the frictional voltage of this sheet-like material was measured by the JIS L1094 B method under the conditions of an air temperature of 20 ° C. and a humidity of 40% was + 14V.
[0051]
The surface of the sheet was ground with sandpaper. The grinding treatment was performed four times in succession, and the grinding powder adhering to the sheet surface, sandpaper, etc. was blown off with an air nozzle, and this was removed by suction from the air duct. Even after the sheet length of 5000 m was continuously processed, the amount of grinding powder deposited on the sheet surface, air nozzle, air duct, etc. was small, and the grinding process could be performed stably. Further, the amount of grinding powder adhering to the sandpaper after the grinding treatment was small, and there was no problem at all for long-time continuous processing.
[0052]
The sheet-like material thus obtained is dyed with a disperse dye and has a density of 0.323 g / cm.^ThreeOf napping leather-like sheet was obtained. The napped leather-like sheet-like material from which this fibrous material was obtained had dense and uniform napping, an elegant appearance, and an appropriate texture.
[0053]
Comparative Example 1
  Examples, except that no antistatic agent is applied before the grinding process1A leather-like sheet was obtained in the same manner. The value obtained by measuring the frictional voltage before grinding of the sheet-like material under the conditions of an air temperature of 20 ° C. and a humidity of 40% by the JIS L1094 B method was + 7300V.
[0054]
When the sheet-like material was ground, the grinding powder adhered to the surface of the sheet, so that it could not be uniformly ground. In addition, a large amount of grinding powder accumulates on the air nozzle, air duct, and sandpaper by continuous processing of about several hundreds of meters. As a result of the accumulated grinding powder reattaching to the sheet, grinding spots are generated and the napped state of the sheet-like material is not good. It became uniform. For this reason, the raised state of the leather-like sheet-like material that has been subjected to the dyeing process is also nonuniform, and has a poor appearance.
[0055]
Comparative Example 2
  Examples except that no antistatic agent and silicone lubricant are applied before the grinding process1A leather-like sheet was obtained in the same manner. The value obtained by measuring the frictional voltage before grinding of the sheet-like material under the conditions of an air temperature of 20 ° C. and a humidity of 40% by the JIS L1094 B method was + 8200V.
[0056]
When the sheet-like material was ground, the grinding powder adhered to the surface of the sheet during the grinding process, and the grinding process could not be performed stably. Furthermore, a large amount of grinding powder accumulates on the air nozzle, air duct, and sandpaper by continuous processing of about several hundred meters, and the napped state of the sheet-like material becomes non-uniform because the accumulated grinding powder reattaches to the sheet. . The surface of the leather-like sheet-like material after the dyeing process was short and non-uniform in length and had a poor appearance.
[0057]
Example2
  Reference exampleA fiber sheet was produced in the same manner as described above.Reference exampleUse the same polyurethane solution asReference exampleIn the same manner as above, the fiber sheet was impregnated with the polyurethane and solidified, and then DMF and polyvinyl alcohol were removed. The sheet-like material is impregnated with a mixed aqueous dispersion of a silicone-based lubricant (SH7036; manufactured by Toray Dow Corning Silicone Co., Ltd.) and a cationic antistatic agent (“Elenite” K-320; manufactured by Takamatsu Yushi Co., Ltd.). And dried after squeezing with a nip roll. At this time, the amounts of the cationic antistatic agent and the silicone lubricant were 0.20% and 0.15%, respectively. In addition, the value when the frictional voltage of this sheet-like material was measured by the JIS L1094 B method under the conditions of an air temperature of 20 ° C. and a humidity of 40% was + 2V.
[0058]
The surface of the sheet was ground continuously with sandpaper four times. At this time, grinding powder adhered to the sheet surface and sandpaper was blown off with an air nozzle and sucked and removed from the air duct. During the grinding process, a small amount of grinding powder was deposited on the sheet surface, air nozzle, air duct, etc., and the grinding process could be performed stably. Further, when the obtained sheet was dyed with a disperse dye, the density was 0.342 g / cm.^ThreeA napping leather-like sheet-like material was obtained. This sheet-like product had dense and uniform napping, an elegant appearance, and an appropriate texture.
[0059]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a napped leather-like sheet-like material having excellent durability, quality, texture, and excellent stability during grinding, for example, It can be suitably used for thin clothes, car seats, chairs, bags, shoes, and other applications.

Claims (4)

Napped leather-like sheet, characterized in that an antistatic agent and a silicone-based lubricant are added to a sheet-like material made of polyurethane containing ultrafine fibers, polycarbonate diol, organic diisocyanate and low-molecular diol, and then subjected to grinding treatment. A method for producing a product. The napped leather according to claim 1 , wherein an antistatic agent is applied so that the frictional voltage measured by the method described in JIS L1094B is within a range of -500 to +5000 V, and then a grinding treatment is performed. A method for producing a sheet-like material. The method for producing a napped-toned leather-like sheet according to claim 1 or 2 , wherein the content of the polyether contained in the polymer diol constituting the polyurethane is 30% by weight or less. The method for producing a napped leather-like sheet-like material according to any one of claims 1 to 3 , wherein the polyurethane comprises a polycarbonate diol, a polyester diol, an organic diisocyanate, and a low molecular diol.