JP4872687B2 - Sheet-like material, method for producing the same, interior material and clothing material using the same, and industrial material - Google Patents

Description

  The present invention relates to a sheet-like article having a good appearance and considering the environment, a method for producing the same, and an interior material, a clothing material, and an industrial material using the sheet-like material.

  A sheet-like material mainly composed of ultrafine fibers and polyurethane has excellent characteristics not found in natural leather, and is widely used in various applications.

  In producing such a sheet-like material, after impregnating a nonwoven fabric made of ultrafine fibers with an organic solvent solution of polyurethane, the fiber sheet-like material is immersed in water or an organic solvent aqueous solution which is a non-solvent of polyurethane. A process of wet coagulating polyurethane is generally employed. As such an organic solvent, a water-miscible organic solvent such as N, N'-dimethylformamide is used as an organic solvent for polyurethane.

  In addition, as a manufacturing method of the ultrafine fiber that constitutes the nonwoven fabric, a method of directly spinning the ultrafine fiber, or a nonwoven fabric made of ultrafine fiber generating fiber such as peelable composite fiber or sea-island composite fiber is produced to produce ultrafine fiber. The method of letting it be mentioned. Here, when comparing the direct spinning method and the method using ultrafine fiber generation type fibers, the fineness of the fineness of the latter is obtained compared to the former, so the surface quality and feel of the sheet-like material are likely to be good. There is. However, an organic solvent such as toluene or trichlorethylene is generally used in the ultrafine treatment of the ultrafine fiber generating fiber.

  That is, in the conventional sheet-like material manufacturing method, a method of using an organic solvent has been mainly used in a polyurethane solvent and fiber ultrafine processing. However, since organic solvents are highly harmful to the human body and the environment, there has been a strong demand for methods that do not use organic solvents in the production of sheet-like materials.

  In recent years, with regard to the use of polyurethane as an organic solvent from such a background, a polyurethane water dispersion in which polyurethane is dispersed in water is used instead of the conventional organic solvent type polyurethane. A method for making fibers finer using hot water or an aqueous alkaline solution by using a hot water soluble component or an alkaline aqueous solution soluble component as an elution component has been studied.

  However, when the polyurethane liquid is impregnated into a nonwoven fabric and solidified, in the case of polyurethane of an organic solvent solution, if wet coagulation is performed by solidifying the polyurethane by immersing it in water or an organic solvent aqueous solution that is a non-solvent for polyurethane, In the case of a polyurethane water dispersion, when the water content of the polyurethane water dispersion moves to the outermost surface of the sheet-like material during heat drying, the polyurethane is also distributed most uniformly in the thickness direction of the nonwoven fabric. A so-called migration phenomenon occurs in the vicinity of the surface. As a result, the texture of the sheet-like material obtained when water-dispersible polyurethane is used becomes very hard, and a sufficiently flexible sheet-like material for practical use has not been obtained.

  In addition, when polyurethane is colored with a dye, there is a problem of so-called dyeing fastness in which color fading, color migration, and the like are likely to occur during washing and dry cleaning. As a method of avoiding the problem of dyeing fastness, washing such as alkali reduction treatment and soaping is performed on the sheet-like material containing the dyed polyurethane for the purpose of removing the dye exhausted by the polyurethane. .

  As a result, the fiber and polyurethane have different dye exhaustion properties, so that the fiber and polyurethane constituting the sheet-like material appear to have different colors, and the problem of inferior quality is likely to occur.

  Such a problem is particularly prominent when water-dispersed polyurethane is used rather than organic solvent-type polyurethane. This is because the water-dispersed polyurethane has a hydrophilic structure and thus has a molecular structure in which a dye can be taken more easily than an organic solvent-type polyurethane.

  The hydrophilic part of the water-dispersible polyurethane includes anions such as carboxylates introduced into the polyurethane molecular structure and nonionics such as polyethylene glycol, which are originally intended to improve the dispersibility of polyurethane in water. Was introduced. Water-dispersed polyurethane can be classified into forced emulsification type polyurethane in which polyurethane is forcibly emulsified and dispersed with a surfactant, and self-emulsification type polyurethane in which polyurethane itself can be emulsified and dispersed without a surfactant, but compared to the former, The latter has more hydrophilic portions, and due to the difference in the degree of hydrophilicity, the hydrophilic portion is more nonionic such as polyethylene glycol than the anionic type such as carboxylate, and more hydrophilic portions. It will have. That is, a water-dispersed polyurethane that is a self-emulsifying polyurethane and has a nonionic system such as polyethylene glycol is the most easily incorporated dye during dyeing and has a low dyeing fastness.

  In dyeing a sheet-like material using a water-dispersed polyurethane that easily incorporates dyes and has low dyeing fastness, studies have been made to reduce the color difference between the fibers constituting the sheet-like material and polyurethane.

  For example, in Patent Document 1, by adding a pigment such as carbon black to a water-dispersed polyurethane liquid in advance and impregnating the non-woven fabric, the color difference between the fibers constituting the sheet-like material and the polyurethane is reduced in dyeing in dark colors. However, only water-dispersed polyurethane having an anionic hydrophilic group such as a carboxylate is assumed.

  In addition, as described above, the water-dispersed polyurethane whose hydrophilic portion is not anionic and nonionic is more easily incorporated with dye, so in order to reduce the color difference between fiber and polyurethane, more carbon black It is necessary to add a pigment such as However, if the amount added is increased, the amount of fiber dropout in the ultrafine process and dyeing process also increases, so it is necessary to add more pigments such as carbon black in consideration of the dropout. Increasing the amount of pigment added in the type polyurethane liquid causes a problem that the pigment tends to settle. Therefore, when considering the production of a sheet-like material using a nonionic water-dispersed polyurethane, it is difficult to produce it stably.

Thus, in consideration of the environment, a sheet-like material obtained by a process not using an organic solvent has not yet been obtained with a good appearance.
JP 2006-37254 A

  In view of the background of such prior art, the present invention provides a sheet-like article having a good appearance and considering the environment, a manufacturing method thereof, an interior material, a clothing material, and an industrial material using the same. It is something to be done.

  The present invention employs the following means in order to solve such problems. That is, the sheet-like material of the present invention is a sheet-like material containing a polymer elastic body mainly composed of nonionic self-emulsifying polyurethane in a nonwoven fabric composed of ultrafine fibers having an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less. The polymer elastic body contains an inorganic pigment, and the self-emulsifying polyurethane has a crosslinked structure by a siloxane bond in its molecular structure.

  The method for producing a sheet-like material of the present invention is a method for producing the sheet-like material according to the present invention by impregnating a non-ionic self-emulsifying polyurethane aqueous dispersion into a fibrous material substrate made of nonwoven fabric. The nonionic self-emulsifying polyurethane water dispersion has a heat-sensitive gelation temperature of 55 ° C. or more and 90 ° C. or less, and the nonionic self-emulsifying polyurethane water dispersion contains a water-dispersible inorganic pigment in the nonionic self-emulsifying polyurethane water dispersion. It is a feature.

  ADVANTAGE OF THE INVENTION According to this invention, the sheet-like thing which has a favorable external appearance and considered the environment, its manufacturing method, the interior material using it, the material for clothing, and the industrial material can be obtained.

  The sheet-like material of the present invention is a sheet-like material containing a polymer elastic body mainly composed of nonionic self-emulsifying polyurethane in a nonwoven fabric composed of ultrafine fibers having an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less. is there.

  The sheet-like material referred to here has an excellent surface appearance such as suede like natural leather, nubuck, silver, etc., and preferably has a smooth touch in the appearance of napped tone such as suede or nubuck. And have excellent lighting effects.

  Examples of the ultrafine fibers constituting the nonwoven fabric constituting the sheet-like material of the present invention include polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyesters such as polyethylene-2,6-naphthalenedicarboxylate, 6-nylon, 66- Various synthetic fibers such as polyamide such as nylon, acrylic, polyethylene, and polypropylene can be used. Of these, polyester fibers such as polyethylene terephthalate, polybutylene terephthalate, and polytrimethylene terephthalate are preferably used from the viewpoints of strength, dimensional stability, light resistance, and dyeability.

  The non-woven fabric may be configured by mixing ultrafine fibers of different materials, and a woven fabric or a knitted fabric may be inserted into the non-woven fabric for the purpose of improving the strength. In addition, the average single fiber fineness of the fiber which comprises a textile fabric or a knitted fabric does not have limitation in particular, 0.001 dtex or more and 1 dtex or less ultrafine fiber may be sufficient.

  It is important that the average single fiber fineness of the ultrafine fibers constituting the nonwoven fabric is 0.001 dtex or more and 0.5 dtex or less from the viewpoint of sheet flexibility and napped quality. Preferably it is 0.3 dtex or less, More preferably, it is 0.2 dtex or less. On the other hand, it is preferably 0.005 dtex or more from the viewpoints of color developability after dyeing, dispersibility of fibers during raising treatment such as grinding with sandpaper, and ease of spreading.

  In addition, the average single fiber fineness of the ultrafine fibers constituting the nonwoven fabric is a scanning electron microscope (SEM) photograph of the surface of the sheet (or nonwoven fabric) when the cross section of the ultrafine fibers is circular or elliptical. The image is taken at a magnification of 2000 times, 100 ultrafine fibers are randomly selected, the fiber diameter is measured, the specific gravity of the material polymer is converted into the fineness, and the average value of the 100 is calculated.

  On the other hand, when the ultrafine fiber constituting the nonwoven fabric has an irregular cross section, the outer peripheral circular diameter of the irregular cross section is calculated as the fiber diameter in the same manner. Furthermore, when a circular cross section and an irregular cross section are mixed, or when those having greatly different finenesses are mixed, 100 are selected and calculated so that each has the same number.

  Regarding the uniformity of the fineness of the ultrafine fibers constituting the nonwoven fabric, the fineness CV in the fiber bundle is preferably 10% or less. Here, the fineness CV is a percentage (%) value obtained by dividing the fineness standard deviation of the fibers constituting the fiber bundle by the average fineness within the bundle, and indicates that the smaller the value, the more uniform. . By setting the fineness CV to 10% or less, the appearance of napping on the surface of the sheet-like material of the present invention becomes graceful, and the dyeing can be made uniform and good. The fineness CV when the cross section of the ultrafine fiber is not circular or an elliptical shape close to a circle can be calculated by the same method as the calculation of the average single fiber fineness.

  The cross-sectional shape of the ultrafine fiber may be a round cross-section, but may be a polygonal cross-section such as an ellipse, a flat shape, or a triangle, or an irregular cross-section such as a sector shape or a cross shape.

  The nonwoven fabric constituting the sheet-like material of the present invention may be either a short fiber nonwoven fabric or a long fiber nonwoven fabric, but a short fiber nonwoven fabric is preferred when emphasis is placed on the texture and quality. Similarly, when emphasis is placed on the texture and quality, the fiber length of the short fibers is preferably 25 mm or more and 90 mm or less in consideration of wear resistance due to entanglement.

  In the present invention, such a nonwoven fabric is impregnated with a nonionic self-emulsifying polyurethane aqueous dispersion as a polymer elastic body, and the nonionic self-emulsifying polyurethane is present in the interior space of the nonwoven fabric. is there.

  The self-emulsifying polyurethane present in the interior space of the nonwoven fabric is preferably not substantially in close contact with the ultrafine fibers constituting the nonwoven fabric, and the self-emulsifying polyurethane preferably has a nonporous structure.

  Since the ultrafine fibers and the self-emulsifying polyurethane are not substantially in close contact with each other, the self-emulsifying polyurethane does not hinder the movement of the ultrafine fibers, so that the sheet-like material is very flexible.

  The term “substantially not adhered” means that the self-emulsifying polyurethane is not adhered to the ultrafine fibers when a scanning electron microscope (SEM) photograph of the cross section of the sheet-like material is observed at a magnification of 300 times. It means that it can be confirmed that a void exists between the self-emulsifying polyurethane and the ultrafine fiber. There may be a partial contact, but basically there is a gap.

  Further, since the self-emulsifying type polyurethane has a non-porous structure and is stronger in physical force such as stagnation than the porous structure, the pilling resistance, wear resistance and the like of the sheet-like material are preferable and preferable. The term “non-porous structure” as used herein means that when a scanning electron microscope (SEM) photograph of a cross section of a sheet-like material is observed at a magnification of 300 times, pores of 5 μm or more cannot be seen in the self-emulsifying polyurethane portion. .

  The self-emulsifying polyurethane present in the internal space of the nonwoven fabric is obtained by impregnating the nonwoven fabric with a nonionic self-emulsifying polyurethane water dispersion. What is the self-emulsifying polyurethane aqueous dispersion in the present invention? It is a polyurethane water dispersion which is stably dispersed in water without using an emulsifier such as a surfactant, and has a hydrophilic so-called internal emulsifier in the self-emulsifying polyurethane molecular structure.

  The self-emulsifying polyurethane is usually handled in a state dispersed in water, and can be obtained from the manufacturer in this state as well, because once dried, it cannot be dispersed in water again. is there.

  The nonionic self-emulsifying polyurethane referred to in the present invention is a self-emulsifying polyurethane and refers to a polyurethane using a nonionic molecular structure such as polyethylene glycol as an internal emulsifier. Cationic internal emulsifiers are inferior in light resistance such as yellowing, and anionic internal emulsifiers may cause adverse effects due to neutralizing agents. That is, when an anionic internal emulsifier is used, a neutralizing agent is required. For example, the neutralizing agent is a tertiary amine such as ammonia, triethylamine, triethanolamine, triisopropanolamine, trimethylamine, or dimethylethanolamine. In some cases, amines are generated and volatilized by the heat generated during film formation and drying, and released outside the system. Therefore, it is indispensable to introduce an apparatus for recovering volatile amines in order to suppress atmospheric emissions and work environment deterioration. In addition, if 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. However, a nonionic internal emulsifier uses a neutralizing agent. Therefore, 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 or calcium hydroxide, or a hydroxide of an alkaline earth metal, the self-emulsifying polyurethane part exhibits alkalinity when wet. However, since the nonionic internal emulsifier does not use a neutralizing agent, there is no need to worry about degradation due to hydrolysis of the self-emulsifying polyurethane.

  The nonionic self-emulsifying polyurethane is 3% by weight or more and 30% by weight based on the total weight of the self-emulsifying polyurethane in order to facilitate thermal gelation with the self-emulsifying polyurethane alone or with an inorganic salt. % Polyethylene glycol or less. If the amount is too small, self-emulsification becomes difficult. If the amount is too large, physical properties such as water resistance and strength of the polyurethane film are likely to decrease. Therefore, the polyethylene glycol content relative to the total weight of the self-emulsifying polyurethane is more preferably 5 % By weight or more and 20% by weight or less.

  As the nonionic self-emulsifying polyurethane of the present invention, those having a structure obtained by appropriately reacting polyol, polyisocyanate, chain extender, internal cross-linking agent and the like in addition to the internal emulsifier can be used.

  As such a polyol, a polycarbonate diol, a polyester diol, a polyether diol, a silicone diol, a fluorine diol, or a copolymer combining these may be used. Of these, polycarbonate diols and polyether diols are preferably used from the viewpoint of hydrolysis resistance, and polycarbonate diols are more preferable from the viewpoints of light resistance and heat resistance.

  Such a polycarbonate-based diol can be produced by a transesterification reaction between an alkylene glycol and a carbonate ester, or a reaction between phosgene or chloroformate ester and an alkylene glycol. Examples of the alkylene glycol include linear chains such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, and 1,10-decanediol. Alkylene glycol, branched alkylene glycol such as neopentyl glycol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 1,4 -Alicyclic diols such as cyclohexanediol, aromatic diols such as bisphenol A, glycerin, trimethylolpropane, pentaerythritol and the like. Either a polycarbonate diol obtained from a single alkylene glycol or a copolymerized polycarbonate diol obtained from two or more types of alkylene glycols may be used.

  Examples of polyisocyanate include aliphatic systems such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and xylylene diisocyanate, and aromatic systems such as diphenylmethane diisocyanate and tolylene diisocyanate, and combinations thereof. Also good. Of these, aliphatic systems such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, and isophorone diisocyanate are preferable from the viewpoint of light resistance.

  Next, chain extenders are obtained by reacting amines such as ethylenediamine, hexamethylenediamine, and methylenebisaniline, diols such as ethylene glycol, neopentyl glycol, and tetraethylene glycol, and further by reacting polyisocyanate with water. Polyamine or the like can be used.

  The internal cross-linking agent is a compound having a functional group capable of cross-linking that is introduced into the molecular structure in advance when synthesizing a self-emulsifying polyurethane as a part of the self-emulsifying polyurethane molecule. In the invention, it is a compound used for introducing a silanol group into a self-emulsifying polyurethane molecular structure. By introducing a silanol group into the molecular structure of the self-emulsifying polyurethane, the self-emulsifying polyurethane existing in the inner space of the nonwoven fabric has a cross-linked structure by siloxane bonds. Durability can be dramatically improved. In addition, the polymer elastic body of the present invention has an inorganic pigment, but the silanol group is introduced into the self-emulsifying polyurethane, whereby the inorganic pigment can be strongly retained, and the content of the inorganic pigment is low. At most, dropping off can be suppressed in the dyeing and washing of the sheet-like material.

  The compound used for introducing the silanol group into the self-emulsifying polyurethane molecular structure is a compound containing an active hydrogen group capable of reacting with at least one isocyanate group and a hydrolyzable silicon group in one molecule. That is.

  The hydrolyzable silicon group here refers to a group in which a hydrolyzable group that is hydrolyzed by moisture is bonded to a silicon atom. Specific examples of the hydrolyzable group include a hydrogen atom and a halogen atom. And generally used groups such as an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an aminooxy group, a mercapto group, and an alkenyloxy group. Among these, an alkoxy group that has low hydrolyzability and is relatively easy to handle is preferable. The hydrolyzable group is bonded to one silicon atom in the range of 1 to 3, but from the viewpoint of reactivity of the hydrolyzable silyl group, water resistance, etc., those having 2 to 3 bonds are preferable. .

  Examples of the active hydrogen group capable of reacting with an isocyanate group include a mercapto group, a hydroxyl group, and an amino group.

  Such hydrolyzable silicon group-containing compounds having a mercapto group as the active hydrogen group and an alkoxy group as the hydrolyzable group include, for example, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-mercaptopropyl. Examples of the hydrolyzable silicon group-containing compound having an amino group as an active hydrogen group and an alkoxy group as a hydrolyzable group include methyldimethoxysilane and γ-mercaptopropylmethyldiethoxysilane. -Aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropyldimethoxysilane, γ- (2-aminoethyl) aminopropyldiethoxysilane Γ-aminopropyltrimethoxy Orchids, .gamma.-aminopropyltriethoxysilane, .gamma.-aminopropyl dimethoxysilane, .gamma.-aminopropyl diethoxy silane and the like. Among these, from the viewpoint of weather resistance and hydrolysis resistance, it is preferable to introduce a hydrolyzable silicon group into the middle part of the self-emulsifying polyurethane molecule, and further a hydrolyzable silicon group-containing compound having two or more active hydrogen groups Is preferred.

  The self-emulsifying polyurethane into which the hydrolyzable silicon group-containing compound has been introduced contains a crosslinked structure due to a siloxane bond in the state of being present in the interior space of the nonwoven fabric. With this cross-linked structure, the polyurethane can be prevented from falling off from the sheet-like material.

  Here, in order to form a siloxane bond, silanol groups directly bonded to the polymer need to be condensed. Therefore, the presence of a siloxane bond indicates that the silanol groups are condensed and a crosslinked structure that bonds the polymers.

  The presence or absence of a siloxane bond can be confirmed by a peak due to the siloxane bond in the measurement of polyurethane by NMR.

  The content of silicon atoms is preferably more than 0% by weight and 1% by weight or less based on the weight of polyurethane. As the number of cross-linked structures due to siloxane bonds increases, the durability of the self-emulsifying polyurethane, such as hydrolysis resistance, improves. However, when the amount is too large, the flexibility of the self-emulsifying polyurethane decreases.

  In addition, content of a silicon atom can be quantified by conducting an elemental analysis of the sheet-like material or polyurethane extracted from the sheet-like material.

  The polymer elastic body of the present invention is mainly composed of nonionic self-emulsifying polyurethane, but may contain polyester, polyamide, polyolefin, silicone, polyurethane and the like.

  The polymer elastic body of the present invention contains an inorganic pigment. By containing such an inorganic pigment, the color difference between the ultrafine fibers of the dyed sheet-like material and polyurethane can be reduced, and a high-grade appearance can be obtained.

  Examples of such inorganic pigments include carbon black, titanium oxide, iron oxide, ultramarine blue, cobalt blue, and the like, but the color difference between the ultrafine fibers of the dyed sheet and polyurethane is particularly clear in dyeing with a dark color. Therefore, carbon black is preferable.

  The content of the inorganic pigment is preferably 0.001% by weight to 20% by weight and more preferably 0.005% by weight to 15% by weight with respect to the weight of the self-emulsifying polyurethane. If the content is too small, the color difference between the ultrafine fibers of the dyed sheet and polyurethane cannot be reduced. Moreover, when there is too much content, it will fall out easily by dyeing | staining, washing, friction, etc.

  The average particle diameter of the inorganic pigment contained in the polymer elastic body of the present invention is preferably 0.01 μm or more and 1 μm or less. The average particle diameter here is the average particle diameter of the pigment in a state where the pigment is present in the polymer elastic body, and is a structure in which a large number of inorganic pigments of the primary particle diameter are aggregated, primary aggregate, secondary aggregate. The average particle diameter in an agglomerated state called secondary particles.

  If the average particle size is too large, when the self-emulsifying polyurethane water dispersion and the inorganic pigment are blended, the inorganic pigment tends to settle, and the nonwoven fabric is impregnated with the self-emulsifying polyurethane aqueous dispersion containing the inorganic pigment. May become insufficient, and coloring and color spots of the sheet-like material may occur. In addition, the average particle diameter of the inorganic pigment contained in the polymer elastic body in the sheet-like material should be confirmed by observing the cross-section and surface of the sheet-like material at 5000 times with a scanning electron microscope (SEM) or the like. Can do.

  Moreover, the presence of coarse particles is not preferable. The term “coarse particles” as used herein refers to those having a particle size of 2 μm or more in an aggregated state called a structure, primary aggregate, secondary aggregate, secondary particle, or the like in which a large number of inorganic pigments having a primary particle diameter are aggregated.

  Next, the manufacturing method of the sheet-like material of this invention is demonstrated.

  The polyurethane water dispersion used in the production of the sheet-like material of the present invention is a polyurethane water dispersion dispersed in water as an emulsion, and is a self-emulsifying polyurethane water dispersion that does not contain an emulsifier such as a surfactant. .

  When a forced emulsification type polyurethane aqueous dispersion containing an emulsifier such as a surfactant is used, the surface of the obtained sheet-like material is sticky due to the emulsifier, so a washing step is required, and the processing step Will increase the cost. In addition, in the forced emulsification type polyurethane water dispersion, the water resistance of the polyurethane film formed into a film is lowered due to the presence of the emulsifier, and therefore, in the dyeing of the sheet-like material containing polyurethane, the polyurethane is not dropped into the dyeing liquid. It is easy to generate and is not preferable.

  The polyurethane water dispersion used in the present invention is a self-emulsifying polyurethane water dispersion, but the self-emulsifying polyurethane water dispersion is a polyurethane in which water is stably dispersed without using an emulsifier such as a surfactant. It is an aqueous dispersion and has a hydrophilic so-called internal emulsifier in the self-emulsifying polyurethane molecular structure.

  The self-emulsifying polyurethane aqueous dispersion of the present invention is a nonionic self-emulsifying polyurethane aqueous dispersion in which the internal emulsifier part is a hydrophilic group such as polyethylene glycol.

  The self-emulsifying polyurethane aqueous dispersion used in the present invention may contain a water-soluble organic solvent in an amount of 40% by weight or less with respect to the aqueous dispersion in order to improve storage stability and film forming property. The content of the organic solvent is preferably 1% by weight or less because of concerns such as the release of the organic solvent into the atmosphere by heating during film formation and the remaining organic solvent in the final product.

  The concentration of the self-emulsifying polyurethane aqueous dispersion (content of the self-emulsifying polyurethane with respect to the self-emulsifying polyurethane aqueous dispersion) is 10% by weight or more and 50% by weight from the viewpoint of storage stability of the self-emulsifying polyurethane aqueous dispersion. % Or less is preferable.

  The self-emulsifying polyurethane aqueous dispersion used in the present invention has a thermal gelation temperature of 55 ° C. or higher and 90 ° C. or lower. By having such a heat-sensitive gelation temperature, it is possible to suppress the polyurethane migration phenomenon when impregnating the nonwoven fabric and heat drying. However, if the thermal gelation temperature is too low, there is a high possibility of gelation in the storage of the polyurethane water dispersion, and if it is too high, the migration phenomenon cannot be suppressed. More preferred.

  Such a self-emulsifying polyurethane water dispersion preferably has a thermal gelation property alone, but for the purpose of imparting a thermal gelation property to the self-emulsification polyurethane water dispersion or lowering the thermal gelation temperature, Inorganic salts such as calcium chloride, sodium sulfate and potassium sulfate may be added.

  The self-emulsifying polyurethane aqueous dispersion of the present invention is used by adding a water-dispersible inorganic pigment. Examples of the inorganic pigment include, as described above, carbon black, titanium oxide, iron oxide, ultramarine blue, cobalt blue, etc., but the color difference between the ultrafine fibers of the dyed sheet and the polyurethane is particularly dyed in a dark color. Therefore, carbon black is preferable.

  As the inorganic pigment, an inorganic pigment used alone or dispersed in water by adding a dispersant is used. When the dispersant is used, the type thereof is not particularly limited, but the amount of the dispersant with respect to the inorganic pigment is preferably 20% by weight or more and 80% by weight or less. If the amount of the dispersing agent is too small, the inorganic pigment cannot be stably dispersed in water.

  The self-emulsifying polyurethane aqueous dispersion of the present invention may be an aqueous dispersion such as polyester, polyamide, polyolefin, silicone, polyurethane and the like, as well as inorganic pigments, dyes, fungicides, antioxidants, ultraviolet absorbers, etc. Light-proofing agent, flame retardant, penetrating agent and lubricant, antiblocking agent such as silica and titanium oxide, antistatic agent, antibacterial agent, deodorant, antifoaming agent such as silicone oil, filler such as cellulose, polyurethane coagulation regulator Etc. may be used.

It is preferable that the manufacturing method of the sheet-like material of this invention is a thing obtained through (1)-(3) in order.
(1) The process of creating a nonwoven fabric using the ultra fine fiber generation type | mold fiber which consists of a combination of 2 or more types of polymeric substances from which solubility with respect to alkaline aqueous solution differs.
(2) A step of impregnating the nonwoven fabric with a self-emulsifying polyurethane aqueous dispersion containing an inorganic pigment.
(3) A step of treating the nonwoven fabric impregnated with the nonionic self-emulsifying polyurethane aqueous dispersion with an alkaline aqueous solution to develop ultrafine fibers.

  By carrying out in the order of (1) to (3), voids can be generated between the self-emulsifying polyurethane and the ultrafine fibers and / or between the ultrafine fibers and the ultrafine fibers, and a very flexible sheet-like material is obtained. be able to. In particular, it is preferable that the ultrafine fiber generating fiber is a sea-island type composite fiber because a self-emulsifying polyurethane and the ultrafine fiber form a structure that is not substantially in close contact with each other, so that a more flexible sheet can be obtained.

  The term “substantially not adhered” means that the self-emulsifying polyurethane is not adhered to the ultrafine fibers when a scanning electron microscope (SEM) photograph of the cross section of the sheet-like material is observed at a magnification of 300 times. It means that it can be confirmed that a void exists between the self-emulsifying polyurethane and the ultrafine fiber. There may be a partial contact, but basically there is a gap.

  As a means for obtaining ultrafine fibers constituting such a nonwoven fabric, ultrafine fiber generating fibers may be used. A nonwoven fabric in which ultrafine fibers are entangled can be obtained by performing ultrafine fiber after entanglement of ultrafine fiber generating fibers in advance.

  As such ultra fine fiber generation type fibers, two or more kinds of thermoplastic polymer components having different solubility in an alkaline aqueous solution are used as sea components / island components, and the sea components are dissolved and removed using an alkaline aqueous solution to make the island components extremely fine. Sea-island type composite fiber used as fiber, peelable composite fiber that splits fiber components into ultrafine fibers by alternately disposing the cross-section of the two-component thermoplastic polymer in a radial or multi-layer form and separating and separating each component Can be adopted. Among them, the sea-island type composite fiber is preferable also from the viewpoint of flexibility and texture of the nonwoven fabric because it can provide an appropriate gap between the island components, that is, between the ultrafine fibers inside the fiber bundle, by removing the sea component. .

  For the sea-island type composite fiber, a sea-island type composite base is used, and a polymer inter-array system in which the two components of the sea and the island are mutually arranged and spun, and the mixed spinning in which the two components of the sea and the island are mixed and spun. Although a system etc. can be used, the sea island type composite fiber by a polymer array system is more preferable at the point from which the ultrafine fiber of uniform fineness is obtained.

  The difference in solubility in an aqueous alkali solution in the present invention means that the dissolution rate differs by 20 times or more, more preferably by 40 times or more under the conditions for causing the ultrafine fibers to appear. If it is less than 20 times, it is difficult to control the fineness of the thermoplastic polymer component having low solubility when developing the ultrafine fiber, which is not preferable.

  The dissolution rate in the alkaline aqueous solution can be calculated from the weight ratio obtained by treating the treatment time as 1 hour in accordance with the chemical resistance test (test solution: sodium hydroxide 10%) of JIS K6911 (1995).

  As a sea component of the sea-island type composite fiber having high solubility in an aqueous alkali solution, from the viewpoint of the dissolution rate in an aqueous alkali solution and spinning stability, polyethylene terephthalate, polybutylene terephthalate, etc., polyester 5-sodium sulfosulfophthalate, polyethylene glycol A copolymerized polyester obtained by copolymerizing 5 to 12 mol% of sodium dodecylbenzenesulfonate, bisphenol A compound, isophthalic acid, adipic acid, dodecadioic acid, cyclohexylcarboxylic acid, or the like, or polylactic acid can be used. In particular, from the viewpoint of heat resistance and solubility in a weak alkaline aqueous solution, it is preferable to use a polyethylene terephthalate copolymer or polylactic acid obtained by copolymerizing 5 to 12 mol% of sodium 5-sulfoisophthalate. These copolymers may be not only binary but also ternary or higher multi-component copolymers.

  The ultrafine fiber-generating fiber is crimped and cut into a predetermined length to obtain a non-woven raw cotton. A usual method can be used for crimping and cutting.

  The obtained raw cotton is made into a web with a cross wrapper or the like, and then the fibers are entangled to make a nonwoven fabric.

  As a method for obtaining a nonwoven fabric by entanglement of fibers, usual methods such as needle punching and water jet punching can be used.

  The obtained non-woven fabric may be subjected to a shrinking treatment by hot water or steam treatment or a compression treatment such as hot pressing in order to improve the fineness of the fibers.

  The non-woven fabric may be obtained by dividing the non-woven fabric in the thickness direction of the non-woven fabric (dividing it into two sheets) or dividing it into several sheets before applying the self-emulsifying polyurethane water dispersion.

  In applying the self-emulsifying type polyurethane water dispersion to the nonwoven fabric, the nonwoven fabric is impregnated with the polyurethane water dispersion or applied to dry heat solidification, and the nonwoven fabric is impregnated with the polyurethane water dispersion and then wet heat solidified. There are a method of heat drying, a method of wet coagulation in hot water and heat drying, and a combination thereof, but there is no particular limitation.

  If the drying temperature is too low, the drying time will be long, and if it is too high, it may cause thermal degradation of the self-emulsifying polyurethane, so that it is preferably 80 ° C. or higher and 180 ° C. or lower. More preferably, it is 90 ° C or higher and 160 ° C or lower.

  When the nonwoven fabric is impregnated with such a self-emulsifying polyurethane aqueous dispersion, the solid content (self-emulsifying polyurethane) content relative to the weight of the nonwoven fabric is preferably 20% by weight or more and 200% by weight or less. By setting it to 20% by weight or more, it is possible to obtain sheet strength and to prevent the fibers from dropping off. By setting it to 200% by weight or less, the texture is prevented from becoming harder than necessary, and a flexible texture and good. Napping quality can be obtained. More preferably, it is 30 wt% or more and 180 wt% or less.

  In the method for producing a sheet-like product of the present invention, it is preferable that a sheet made of ultrafine fiber-generating fibers impregnated with a self-emulsifying polyurethane aqueous dispersion is treated with an alkaline aqueous solution to develop ultrafine fibers.

  The alkaline aqueous solution here is not particularly limited, and an aqueous solution such as sodium hydroxide or potassium hydroxide, an ammonia salt, or the like can be used.

  The concentration of the alkaline aqueous solution is not particularly limited as long as ultrafine fibers can be expressed, but is preferably 0.05 mol / L or more and 10 mol / L or less.

  The treatment with an alkaline aqueous solution is to immerse a sheet made of ultrafine fiber-generating fibers after application of a self-emulsifying polyurethane and to perform a constriction liquid. In the case of a sea-island type composite fiber divided by physical force, the sea component dissolved in alkaline water is eluted to generate ultrafine fibers, so the method is not particularly limited, but for example, a liquid dyeing machine or A refining apparatus etc. and the process using those combination are mentioned.

  The temperature and time in the treatment using a liquid dyeing machine are preferably 50 ° C. or higher and 140 ° C. or lower and 5 minutes or longer and 90 minutes or shorter, respectively.

  In addition, for the purpose of improving the generation of ultrafine fibers, heat treatment, steam treatment, treatment with addition of a penetrant such as a surfactant may be performed as appropriate, and treatment with an acidic aqueous solution having a pH of 3 or less is performed in advance. After performing, you may process by alkaline aqueous solution.

  The nonwoven fabric obtained in this way, that is, a sheet-like material, may be a leather-like sheet-like material having a nap-like tone having naps of ultrafine fibers on at least one side.

  The raising treatment for forming napping on the surface of the sheet-like material can be performed by a grinding method using a sandpaper or a roll sander.

  It is preferable to apply an antistatic agent before the raising process, because the grinding powder generated from the sheet-like material by grinding tends to be difficult to deposit on the sandpaper.

  In addition, the sheet-like material may be obtained by half cutting or dividing into several sheets in the sheet thickness direction before performing the raising treatment.

  Further, the sheet-like material may be dyed. As the dyeing method, it is preferable to use a liquid dyeing machine because the sheet-like material can be further softened by dyeing the sheet-like material and simultaneously giving a stagnation effect. As the liquid dyeing machine, a normal liquid dyeing machine can be used.

  If the dyeing temperature is too high, the self-emulsifying polyurethane may be deteriorated. Conversely, if the dyeing temperature is too low, the dyeing to the fibers becomes insufficient. The following is preferable, and 110 ° C. or higher and 130 ° C. or lower is more preferable.

  The dye is not particularly limited and may be selected according to the ultrafine fiber constituting the sheet-like material. For example, a polyester-based ultrafine fiber is a disperse dye, and a polyamide-based ultrafine fiber is a dye such as an acid dye or a metal-containing dye, And dyes combining them can be used.

  When dyed with disperse dyes, reduction washing may be performed after dyeing.

  Moreover, it is preferable to use a dyeing assistant during dyeing for the purpose of improving the uniformity and reproducibility of dyeing. Furthermore, finishing agents such as softeners such as silicone, antistatic agents, water repellents, flame retardants, light proofing agents, deodorants, and anti-pilling agents may be applied. But you can.

  The sheet-like material obtained by the manufacturing method of the present invention is an interior material having a very elegant appearance as a skin material for furniture, chairs, wall materials, seats, ceilings, interiors, etc. in vehicle interiors of automobiles, trains, airplanes, etc. , Shirts, jackets, casual shoes, sports shoes, men's shoes, women's shoes, upper and trim of shoes, bags, belts, wallets, etc., clothing materials used for some of them, wiping cloth, polishing cloth, etc. It can be suitably used as an industrial material.

EXAMPLES Hereinafter, although this invention is demonstrated further more concretely using an Example, this invention is not limited only to a following example.
[Evaluation methods]
(1) Average single fiber fineness A scanning electron microscope (SEM) photograph of the surface of a non-woven fabric or sheet-like material was taken at a magnification of 2000 times, and 100 fibers having a circular shape or a nearly elliptic shape were randomly selected, and the fiber diameter was selected. It measured and converted into the fineness from the specific gravity of the raw material polymer of fiber, and also calculated by calculating the average value of 100 pieces.

(2) Fineness CV
The cross section inside the nonwoven fabric, that is, the sheet-like material was observed with a scanning electron microscope (SEM) at a magnification of 2000 times, and from the photograph, the fiber diameter of the ultrafine fibers constituting one bundle of bundled fibers was measured. The value obtained by converting the fiber diameter to the fineness of each single fiber and dividing the fineness standard deviation of the fibers constituting the fiber bundle by the average fineness in the bundle was expressed as a percentage (%). The same measurement was performed on the five bundle fibers, and the average value was defined as the fineness CV.

(3) Sheet-like structure The cross section inside the sheet-like article was observed with a scanning electron microscope (SEM) at a magnification of 300 times, and the adhesion between polyurethane and ultrafine fibers and the structure of the polyurethane portion were judged from the photograph.

(4) Confirmation of siloxane bond and quantification of silicon atom content Polyurethane sampled from 3 or more random locations of the sheet-like material is measured by NMR, and at least any measurement confirms a peak due to the siloxane bond. This confirmed the presence or absence of a siloxane bond. Further, elemental analysis of the sheet-like material or polyurethane extracted from the sheet-like material was performed at least 5 times, and the average value was quantified as the silicon atom content.

(5) Confirmation of polyethylene glycol In the measurement by NMR for polyurethane sampled from three or more random parts of the sheet-like material, a peak caused by a reference substance and a peak caused by polyethylene glycol (for example, an ethylene chain portion adjacent to an oxygen atom) The area of protons) was calculated and averaged.

(6) Average particle diameter of inorganic pigment in polymer elastic body At least five portions of the cross-section and surface of the sheet-like material were observed at 5000 times with a scanning electron microscope (SEM) or the like, and the average value was defined as the average particle diameter .

(7) Thermal gelation temperature of self-emulsifying polyurethane water dispersion 10 g of a self-emulsifying polyurethane water dispersion with a solid content concentration of 10% by weight is placed in a test tube and heated in a constant temperature hot water bath at 95 ° C. The temperature at which the emulsified polyurethane aqueous dispersion lost its fluidity and gelled and solidified was defined as the thermal gelation temperature.

(8) Amount of organic solvent contained in self-emulsifying polyurethane water dispersion In polyurethane water dispersion with solid concentration used for impregnation, gas chromatography analysis of dispersion medium (263-50, manufactured by HITACHI, column: depending on the type of organic solvent Although different, the amount of the organic solvent contained was quantified by using PEG20M in the case of N, N-dimethylformamide.

(9) Appearance quality 10 healthy adult men and 10 adult women each, with a total of 20 evaluators, the surface quality of the sheet-like material was visually determined in five stages, and the average value was taken as the appearance quality. .

Class 5: No color difference is observed between the ultrafine fiber and the polymer elastic body. Class 4: Color difference is very slight between the ultrafine fiber and the polymer elastic body. Class 3: Color difference is slightly visible between the ultrafine fiber and the polymer elastic body. 2nd grade: Color difference between ultrafine fiber and polymer elastic body can be seen 1st grade: Color difference between ultrafine fiber and polymer elastic body can be seen clearly (10) Texture 10 healthy adult men and 10 adult women each, 20 people in total As an evaluator, the evaluation of the texture was graded on a tactile basis in five stages, and the average value was taken as the texture.

5th grade: very flexible 4th grade: flexible 3rd grade: slightly flexible 2nd grade: hard 1st grade: very hard [Notation of chemical substances]
The meanings of the abbreviations of chemical substances used in each example and comparative example are as follows.
PHC: Polyhexamethylene carbonate polyol H12MDI: Dicyclohexylmethane diisocyanate HDI: Hexamethylene diisocyanate PET: Polyethylene terephthalate Ny6: 6-Nylon PEG: Polyethylene glycol [Polyurethane species]
The composition of the polyurethane water dispersion used in Examples and Comparative Examples is as follows. The solid content concentration of each solution was 30% by weight. Furthermore, Table 1 shows the characteristics of each polyurethane aqueous dispersion.

(1) Polyurethane aqueous dispersion I (PU-I)
Polyisocyanate: H12MDI
Polyol: PHC
Internal emulsifier: Diol compound having polyethylene glycol in the side chain Chain extender: Ethylenediamine
Internal cross-linking agent: γ- (2-aminoethyl) aminopropyltrimethoxysilane-containing organic solvent: 0.1% by weight
Inorganic pigment: Water dispersible carbon black Amount of inorganic pigment added to polyurethane weight: 12% by weight.

(2) Polyurethane aqueous dispersion II (PU-II)
Polyisocyanate: H12MDI
Polyol: PHC
Internal emulsifier: Diol compound having polyethylene glycol in the side chain Chain extender: Ethylenediamine Internal cross-linking agent: γ- (2-aminoethyl) aminopropyltrimethoxysilane-containing organic solvent: 0.1% by weight
Inorganic pigment: Water dispersible carbon black Amount of inorganic pigment added to polyurethane weight: 0.1% by weight.

(3) Polyurethane aqueous dispersion III (PU-III)
Polyisocyanate: HDI
Polyol: PHC
Internal emulsifier: Diol compound having polyethylene glycol in the side chain Chain extender: Ethylenediamine Internal cross-linking agent: γ- (2-aminoethyl) aminopropyltrimethoxysilane-containing organic solvent: 0.2% by weight
Inorganic pigment: Water-dispersible cobalt blue Amount of inorganic pigment added to polyurethane weight: 15% by weight.

(4) Polyurethane aqueous dispersion IV (PU-IV)
Polyisocyanate: H12MDI
Polyol: PHC
Internal emulsifier: Diol compound having polyethylene glycol in the side chain Chain extender: Ethylene diamine Internal cross-linking agent: None Contained organic solvent: 0.2% by weight
Inorganic pigment: Water dispersible carbon black Amount of inorganic pigment added to polyurethane weight: 12% by weight.

(5) Polyurethane aqueous dispersion V (PU-V)
Polyisocyanate: H12MDI
Polyol: PHC
Internal emulsifier: Diol compound having polyethylene glycol in the side chain Chain extender: Ethylenediamine Internal cross-linking agent: γ- (2-aminoethyl) aminopropyltrimethoxysilane-containing organic solvent: 0.2% by weight
Inorganic pigment: No addition.

(6) Polyurethane aqueous dispersion VI (PU-VI)
Polyisocyanate: H12MDI
Polyol: PHC
Internal emulsifier: None External emulsifier: Nonionic surfactant Internal cross-linking agent: None Contained organic solvent: 0.8% by weight
Inorganic pigment: Water dispersible carbon black Amount of inorganic pigment added to polyurethane weight: 12% by weight.

[Example 1]
Polyethylene terephthalate copolymerized with 8 mol% of sodium 5-sulfoisophthalate is composed of 45 parts of sea component and 55 parts of PET as island component, and 36 islands are contained in one filament. Average fineness Using 2.8 dtex sea-island fiber staples (fiber length 51 mm), a web was formed through a card and a cross wrapper, and a nonwoven fabric was formed by needle punching.

  This non-woven fabric was shrunk by treating in hot water at 90 ° C. for 2 minutes and dried at 100 ° C. for 5 minutes. The polymer is then impregnated with polyurethane aqueous dispersion I (PU-I) and dried with hot air at a drying temperature of 125 ° C. for 10 minutes, so that the weight of the elastic polymer is 80% by weight relative to the weight of the island component of the nonwoven fabric. A sheet provided with an elastic body was obtained.

  Next, this sheet was immersed in a 15 g / L aqueous sodium hydroxide solution heated to 90 ° C. and treated for 30 minutes to obtain a sea removal sheet from which sea components of sea-island fibers were removed. By observation with a scanning electron microscope (SEM) on the surface of the sea removal sheet, it was confirmed that the average single fiber fineness was 0.04 dtex and the fineness CV was 7.4%. Moreover, it was confirmed by scanning electron microscope (SEM) observation of the cross section of the sheet that the polyurethane and the ultrafine fiber were not in close contact, and the average particle size of carbon black in the polyurethane was confirmed to be 0.30 μm.

  Then, the sea removal sheet is cut in half in the thickness direction, and the surface opposite to the half-cut surface is brushed by grinding using a 240 mesh endless sandpaper, and then dyed with a dark brown disperse dye in a circular dyeing machine. To obtain a sheet.

  The appearance quality and texture of the obtained sheet were good.

[Example 2]
Similar to Example 1 except that polyurethane water dispersion II (PU-II) was used instead of polyurethane water dispersion I (PU-I) in Example 1 and ocher disperse dye was used at the time of dyeing. Thus, a sheet-like material was obtained.

  By observation with a scanning electron microscope (SEM) of the cross section of the sheet, it was confirmed that the polyurethane and the ultrafine fiber were not in close contact with each other, and the average particle diameter of carbon black in the polyurethane was confirmed to be 0.16 μm.

  The appearance quality and texture of the obtained sheet were good.

[Example 3]
A sea island type fiber staple (fiber) in which polylactic acid is 20 parts as sea component and Ny6 is 80 parts as island component, and 16 islands are contained in one filament, and the average fineness is 3.8 dtex. A web was formed through a card and a cross wrapper using a long 51 mm), and a nonwoven fabric was formed by needle punching.

  This non-woven fabric was shrunk by treating in hot water at 90 ° C. for 2 minutes and dried at 100 ° C. for 5 minutes. Next, the polymer elastic body is impregnated with polyurethane aqueous dispersion III (PU-III) and dried with hot air at a drying temperature of 100 ° C. for 10 minutes so that the weight of the polymer elastic body is 85% by weight with respect to the weight of the nonwoven fabric. A given sheet was obtained.

  Next, this sheet was immersed in an aqueous solution of sodium hydroxide having a concentration of 40 g / L heated to 90 ° C. and treated for 30 minutes to obtain a sea removal sheet from which sea components of sea-island fibers were removed. By observation with a scanning electron microscope (SEM) on the surface of the sea removal sheet, it was confirmed that the average single fiber fineness was 0.2 dtex and the fineness CV was 7.5%. Moreover, it was confirmed by scanning electron microscope (SEM) observation of the cross section of the sheet that the polyurethane and the ultrafine fiber were not in close contact, and the average particle size of cobalt blue in the polyurethane was confirmed to be 0.62 μm.

  Then, the sea removal sheet is cut in half in the thickness direction, and the surface opposite to the half-cut surface is brushed by grinding using a 240 mesh endless sandpaper, and then dyed with a blue disperse dye in a circular dyeing machine. A sheet was obtained.

  The appearance quality and texture of the obtained sheet were good.

[Comparative Example 1]
In Example 1, a sheet-like material was obtained in the same manner as in Example 1 except that the polyurethane water dispersion IV (PU-IV) was used instead of the polyurethane water dispersion I (PU-I).

  By observation with a scanning electron microscope (SEM) of the cross section of the sheet, it was confirmed that the polyurethane and the ultrafine fiber were not in close contact with each other, and the average particle size of carbon black in the polyurethane was confirmed to be 0.28 μm.

  It was confirmed that carbon black was removed during dyeing, and the appearance quality of the obtained sheet-like product was poor.

[Comparative Example 2]
In Example 1, a sheet-like material was obtained in the same manner as in Example 1 except that the polyurethane water dispersion V (PU-V) was used instead of the polyurethane water dispersion I (PU-I).

  It was confirmed by observation with a scanning electron microscope (SEM) of the cross section of the sheet that the polyurethane and the ultrafine fibers were not in close contact.

  The appearance quality of the obtained sheet-like material was poor.

[Comparative Example 3]
In Example 1, a sheet-like material was obtained in the same manner as in Example 1 except that the polyurethane water dispersion VI (PU-VI) was used instead of the polyurethane water dispersion I (PU-I).

  By observation with a scanning electron microscope (SEM) of the cross section of the sheet, it was confirmed that the polyurethane and the ultrafine fibers were not in close contact with each other, and the average particle size of carbon black in the polyurethane was confirmed to be 0.26 μm.

  The removal of polyurethane and carbon black was observed during the seawater removal process and dyeing with an alkaline solution.

  The appearance quality of the obtained sheet-like material was poor.

Claims (16)

A sheet-like material containing a polymer elastic body mainly composed of nonionic self-emulsifying polyurethane in a nonwoven fabric composed of ultrafine fibers having an average single fiber fineness of 0.001 dtex or more and 0.5 dtex or less, the polymer elastic body Contains an inorganic pigment, and the self-emulsifying polyurethane has a cross-linked structure due to a siloxane bond in its molecular structure. The sheet-like material according to claim 1, wherein the inorganic pigment is carbon black. The sheet-like product according to claim 1 or 2, wherein the content of the inorganic pigment is 0.001 wt% or more and 20 wt% or less with respect to the polyurethane weight. The sheet-like material according to any one of claims 1 to 3, wherein the self-emulsifying polyurethane part has a nonporous structure. The sheet-like material according to any one of claims 1 to 4, wherein the self-emulsifying polyurethane and the ultrafine fibers are not substantially adhered to each other. The content of silicon atoms in the molecular structure of the self-emulsifying polyurethane is more than 0% by weight and 1% by weight or less based on the weight of the polyurethane. Sheet material. The sheet-like material according to any one of claims 1 to 6, wherein the self-emulsifying polyurethane has 3 to 30% by weight of polyethylene glycol with respect to the total weight of the polyurethane. A method for producing a sheet-like product according to any one of claims 1 to 7, wherein a non-ionic self-emulsifying polyurethane aqueous dispersion is impregnated into a fibrous material substrate made of non-woven fabric, wherein the nonionic self-emulsifying polyurethane Production of a sheet-like product, wherein the aqueous dispersion has a thermal gelation temperature of 55 ° C. or higher and 90 ° C. or lower, and the nonionic self-emulsifying polyurethane aqueous dispersion contains a water-dispersible inorganic pigment. Method. The manufacturing method of the sheet-like material according to claim 8, wherein the following steps (1) to (3) are performed in this order.
(1) The process of creating a nonwoven fabric using the ultra fine fiber generation type | mold fiber which consists of a combination of 2 or more types of polymeric substances from which solubility with respect to alkaline aqueous solution differs.
(2) A step of impregnating the nonwoven fabric with a self-emulsifying polyurethane aqueous dispersion containing an inorganic pigment.
(3) A step of treating the nonwoven fabric impregnated with the nonionic self-emulsifying polyurethane aqueous dispersion with an alkaline aqueous solution to develop ultrafine fibers. The method for producing a sheet-like material according to claim 8 or 9, wherein the inorganic pigment is carbon black. The method for producing a sheet-like material according to any one of claims 8 to 10, wherein the ultrafine fiber generating fiber is a sea-island type composite fiber. The sea component of the sea-island composite fiber is mainly composed of terephthalic acid and ethylene glycol, and is composed of a copolyester containing 5 to 12 mol% sodium 5-sulfoisophthalate with respect to the total acid component. The manufacturing method of the sheet-like material in any one of Claims 8-11. The method for producing a sheet-like product according to any one of claims 8 to 12, wherein the self-emulsifying polyurethane aqueous dispersion contains an organic solvent in a proportion of 1% by weight or less. The interior material characterized by using the sheet-like material in any one of Claims 1-7 as a skin material. A clothing material using the sheet-like material according to any one of claims 1 to 7. An industrial material using the sheet-like material according to claim 1.