KR20160127019A - Sheet-like material and method for producing same - Google Patents

Abstract

The present invention relates to a method for producing a sheet-like material without using an organic solvent in the production process, and provides a sheet-shaped article having excellent surface quality and feel and a method for producing the same. The sheet product of the present invention is a sheet product obtained by imparting a polymeric elastomer having a hydrophilic group as a binder to a fibrous base material containing microfine fibers and is a sheet of a polymeric elastomer , And an occupation ratio of a portion having a sectional area of at least 50 mu m ² independently is not less than 0.1% and not more than 5.0% with respect to the area of the cross section of the artificial leather in the observation visual field. The method for producing a sheet-like product of the present invention is a method for producing a sheet-like product in which a polymeric elastomer having a hydrophilic group is bonded to a fibrous base material containing microfine fibers as a binder, comprising the steps of: The resin dispersion is added to the fibrous base, and the polymeric elastomer is solidified in hot water at a temperature of 50 to 100 캜.

Description

[0001] SHEET-LIKE MATERIAL AND METHOD FOR PRODUCING SAME [0002]

TECHNICAL FIELD The present invention relates to a method for producing a sheet-like product in consideration of an environment in which an organic solvent is not used in the manufacturing process, and more particularly to a sheet-shaped product having excellent surface quality and feel and a method for producing the same.

Background Art [0002] A fibrous base material such as a nonwoven fabric and a sheet material including a polyurethane have excellent characteristics not found in natural leather and are widely used for various applications such as artificial leather. In particular, sheet products using polyester fiber-based substrates have been widely used every year because of their excellent light resistance, such as medical (clothing), chair covers, and automobile interior materials.

In the production of such a sheet product, a combination of a step of impregnating a fibrous substrate with an organic solvent solution of polyurethane, and a step of wet-coagulating the polyurethane by immersing the obtained fibrous substrate in a nonpolar solvent of polyurethane or an aqueous solution of an organic solvent And is generally adopted. In this case, a water-miscible organic solvent such as N, N-dimethylformamide is used as the organic solvent which is a solvent of the polyurethane. However, in general, since organic solvents are highly harmful to humans and the environment, there is a strong demand for a method that does not use organic solvents in the production of sheet-like products.

As a specific solution, a method of using a water-dispersible polyurethane in which a hydrophilic group is contained in a molecule and a polyurethane resin is dispersed in water is being studied instead of a conventional organic solvent-based polyurethane.

However, there is a problem that impregnation of a water-dispersible polyurethane dispersion in which a water-dispersible polyurethane dispersed in a liquid is impregnated into a fibrous base material, and in which a polyurethane is coagulated, tends to make the texture hard.

One of the main reasons for this is the difference in the coagulation method between the two. That is, the coagulation method of the organic solvent-based polyurethane liquid is a so-called wet coagulation method in which the polyurethane molecules dissolved in the organic solvent are replaced by water and solidified, and a porous film having a low density is formed by the polyurethane film. Therefore, even when the polyurethane is impregnated into the fibrous base material and solidified, the area of adhesion between the fibers and the polyurethane decreases, resulting in a smooth sheet product.

On the other hand, the water-dispersed polyurethane is mainly a so-called wet heat coagulation system in which the water dispersion state of the aqueous dispersion type polyurethane dispersion liquid is collapsed by coagulation of the polyurethane emulsions, and the resulting polyurethane film structure has a high density (Non-porous) membrane. As a result, the adhesion between the fibrous substrate and the polyurethane is dense and the entangled portions of the fibers are firmly gripped, so that the texture is hardened.

In order to suppress the improvement of the feeling due to the application of the water-dispersible polyurethane, that is, to suppress the retention of the fiber inter-woven points due to the polyurethane, there has been proposed a technique of making the structure of the polyurethane in the fibrous substrate a porous structure.

Specifically, a method has been proposed in which a water-dispersible polyurethane liquid containing a foaming agent is added to a fibrous base material such as a nonwoven fabric, and the foaming agent is foamed by heating to make the polyurethane structure in the fibrous base material porous Patent Document 1). According to this proposal, by making the water-dispersible polyurethane porous, it is possible to obtain a sheet product having a good touch feeling, which has a small adhesive area between the fiber and the polyurethane and weak gripping power of the inter-woven points of the fibers, Compared with the case where polyurethane is added, the flexibility tends to be insufficient.

Separately, as a technique of making the structure of the polyurethane in the fibrous substrate a porous structure, there has been proposed a method in which an aqueous dispersion of a polyurethane dispersion containing a associative thickener is added to a fibrous base material and coagulated by wet heat treatment to polydisperse the aqueous dispersion polyurethane (See Patent Document 2). Also in this proposal, by making the water-dispersible polyurethane porous, it is possible to obtain a sheet-like article having a good touch feeling, which has a small adhesive area between the fiber and the polyurethane and weak gripping power of the inter- Compared with the case where a solvent-based polyurethane is added, flexibility is still insufficient.

Japanese Patent Application Laid-Open No. 2011-214210 Japanese Patent No. 4042016

Accordingly, it is an object of the present invention to provide an artificial leather having an excellent uniformity in appearance compared with an artificial leather to which an organic solvent-based polyurethane is applied by a manufacturing process considering an environment in consideration of the background of the prior art, And a process for producing the same.

It is also an object of the present invention to provide a sheet product having folded wrinkle recovery and flexibility which is very similar to artificial leather to which polyurethane is applied by applying water-dispersed polyurethane and solvent-based polyurethane, and a manufacturing method thereof I have to.

A sheet product of the present invention is a sheet product obtained by imparting a polymeric elastomer having a hydrophilic group as a binder to a fibrous substrate containing microfine fibers and / or microfine fiber bundles as a binder, The occupation ratio of a portion having a cross sectional area of at least 50 mu m ² independently of the polymer elastic body observed in the cut surface is not less than 0.1% and not more than 5.0% with respect to the area of the cross section of the artificial leather in the observation field of view And the like.

According to a preferred form of the sheet-like material of the present invention, 1% or more and 35% or less of the outer periphery of the microfine fiber and / or microfine fiber bundle cross-section is covered with the polymeric elastomer film on the cross section taken along the thickness direction of the sheet- .

According to a preferred form of the sheet-like material of the present invention, the polymeric elastomer is a sheet product according to claim 1 or 2, which has a structure crosslinked by a crosslinking agent.

In order to achieve the above object, the present invention provides a method for producing a sheet-like material, wherein a fibrous base material containing microfine fibers is provided with a polymeric elastomer having a hydrophilic group as a binder, To a fibrous base material and subjecting the fibrous base material to coagulation of the elastomeric polymer in hot water at a temperature of 50 to 100 캜.

According to a preferred embodiment of the method for producing a sheet-like product of the present invention, the aqueous resin dispersion liquid exhibits a non-Newtonian property.

According to a preferred embodiment of the method for producing a sheet of the present invention, the thickener is a nonionic thickener.

According to a preferred embodiment of the method for producing a sheet-like product of the present invention, the aqueous resin dispersion liquid exhibits thixotropic properties.

According to a preferred embodiment of the method for producing a sheet-like product of the present invention, the thickening agent contained in the aqueous resin dispersion is a thickening polysaccharide.

According to a preferred embodiment of the method for producing the sheet of the present invention, the thickener is guar gum.

According to a preferred embodiment of the method for producing a sheet-like product of the present invention, the aqueous resin dispersion contains a heat coagulant.

According to a preferred embodiment of the method for producing a sheet-like product of the present invention, the aqueous resin dispersion contains a crosslinking agent.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to achieve folded wrinkle recovery and flexibility, which are very similar to the case where an organic solvent-based polyurethane is added to a fibrous substrate by forming a porous structure of the water dispersed polyurethane by an environment- Also, it has a bristle length uniformly equal to that of an artificial leather to which an organic solvent-based polyurethane is applied. Thus, a sheet product having an excellent surface quality with excellent fiber denseness and an excellent feeling of being flexible and having a folded wrinkle recovery property can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a SEM photograph of a section of artificial leather obtained in Example 13 of the present invention. Fig.
Fig. 2 is a SEM photograph of a section of artificial leather obtained in Comparative Example 4 of the present invention. Fig.
FIG. 3 is a SEM photograph of a reference SEM image for explaining an outline of a method of calculating the occupation ratio of a non-porous mass of a polymeric elastomer of 50 μm ² or more.
FIG. 4 is a SEM photograph of a reference SEM image for explaining a method of calculating the polymeric elastomer film ratio at the cross section of the superfine fiber.

[About sheet products]

First, the sheet product of the present invention will be described.

The sheet product of the present invention is obtained by imparting a polymeric elastomer containing a hydrophilic group-containing resin such as an aqueous dispersion type polyurethane to a fibrous substrate such as a nonwoven fabric containing microfine fibers as a binder.

Examples of the fiber constituting the fibrous base material include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate and polylactic acid, polyamides such as 6-nylon and 66-nylon, acryl, polyethylene, And fibers containing a melt-spinnable thermoplastic resin such as thermoplastic cellulose. Among them, polyester fibers are preferably used in terms of strength, dimensional stability and light fastness. Further, the fibrous substrate may be formed by mixing fibers of different materials.

The cross-sectional shape of the microfine fibers may be a circular cross section, but a cross-sectional shape such as an ellipse, a flat or triangular polygonal shape, a fan shape, and a cross shape may be employed.

The average single fiber diameter of the microfine fibers constituting the fibrous substrate is preferably 0.1 to 7 mu m. By setting the average single fiber diameter to be preferably 7 占 퐉 or less, more preferably 6 占 퐉 or less, further preferably 5 占 퐉 or less, it is possible to obtain a sheet product having excellent flexibility and upholstery quality. On the other hand, by setting the average single fiber diameter to 0.1 mu m or more, preferably 0.3 mu m or more, more preferably 0.7 mu m or more, and particularly preferably 1 mu m or more, the coloring property after dyeing or the grinding It is excellent in dispersibility and easiness of solubility of the multipurpose fibers at the time of napping treatment.

As the form of the fibrous substrate including the microfine fibers, a fabric, a knitted fabric, a nonwoven fabric, or the like can be employed. Among them, a nonwoven fabric is preferably used because the surface quality of the sheet is good when the surface is brushed.

As the nonwoven fabric, both a single-spun nonwoven fabric and a long-spun nonwoven fabric are used, but a single-spun nonwoven fabric is preferably used from the viewpoint of feel and dignity.

The fiber length of the short fibers in the single-fiber nonwoven fabric is preferably 25 mm or more and 90 mm or less, and more preferably 35 mm or more and 75 mm or less. By setting the fiber length to 25 mm or more, it is possible to obtain a sheet product excellent in abrasion resistance by entanglement. Further, by setting the fiber length to 90 mm or less, it is possible to obtain a sheet product superior in texture and durability.

When the fibrous substrate containing microfine fibers is a nonwoven fabric, the nonwoven fabric preferably has a structure in which microfine fibers (fiber bundles) are entangled. The superfine fibers are entangled in a bundle state to improve the strength of the sheet. This type of nonwoven fabric can be obtained by preliminarily entangling the ultrafine fiber-forming fibers and then expressing the ultrafine fibers.

When the microfine fibers or the fiber bundles thereof constitute a nonwoven fabric, a fabric or a knitted fabric can be inserted into the nonwoven fabric for the purpose of improving the strength or the like. The average short fiber diameter of the fibers constituting the fabric or the knitted fabric is preferably about 0.1 to 10 mu m.

Examples of the hydrophilic group-containing resin which is an elastomer used as a binder in the sheet material of the present invention include an aqueous dispersion type silicone resin, an aqueous dispersion type acrylic resin and an aqueous dispersion type urethane resin and copolymers thereof. Among them, Polyurethane is preferably used.

As the polyurethane, a resin obtained by a reaction between a high molecular weight polyol having a number average molecular weight of preferably 500 or more and 5000 or less, an organic polyisocyanate, and a chain extender is preferably used. To increase the stability of the aqueous dispersion type polyurethane dispersion, an active hydrogen component-containing compound having a hydrophilic group is used in combination. By setting the number average molecular weight of the high molecular weight polyol to 500 or more, more preferably 1,500 or more, it is possible to prevent the feel from becoming stiff and the number average molecular weight to be 5,000 or less, more preferably 4,000 or less, Lt; / RTI >

As the polyether polyol among the above-mentioned polymer polyols, a polyhydric alcohol or a polyamine is used as an initiator and a monomer such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, tetrahydrofuran, epichlorohydrin and cyclohexylene is added Polymerized polyols, and polyols obtained by ring-opening polymerization of the above monomers with a catalyst such as a protonic acid, a Lewis acid and a cation catalyst. Specific examples thereof include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and copolymerized polyols obtained by combining them.

Examples of the polyester-based polyol include a polyester polyol obtained by condensing various low molecular weight polyols and polybasic acids, and a polyol obtained by depolymerizing a lactone.

Examples of the low molecular weight polyol include ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,9-nonanediol, 1,10-decanediol, and other straight chain alkylene glycols such as neopentyl glycol, 3-methyl-1,5-pentanediol, 2,4- 2-methyl-1,8-octanediol; alicyclic diols such as 1,4-cyclohexanediol; and aromatic diols such as 1,4-bis (? -Hydroxyethoxy) Alcohol, and the like. Adducts in which various alkylene oxides are added to bisphenol A can also be used as low molecular weight polyols.

Examples of the polybasic acid include succinic acid, maleic acid, adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid and hexahydroisophthalic acid And the like can be mentioned.

Examples of the polylactone polyol include a polylactone polyol obtained by ring-opening polymerization of a mixture of two or more such as? -Butyrolactone,? -Valerolactone,? -Caprolactone and the like using a polyhydric alcohol as an initiator.

Examples of the polycarbonate-based polyol include compounds obtained by reacting a polyol with a carbonate compound such as dialkyl carbonate, diaryl carbonate or the like.

Production of polycarbonate polyol As the polyol used as raw material, a polyol exemplified in the raw material for producing a polyester polyol can be used. As the dialkyl carbonate, dimethyl carbonate or diethyl carbonate can be used. As the diaryl carbonate, diphenyl carbonate and the like can be mentioned.

In the polymeric elastomer having a hydrophilic group used in the present invention, for example, an active hydrogen-containing group containing a hydrophilic group may be exemplified as a component containing a hydrophilic group in a polymeric elastomer. Examples of the hydrophilic group-containing active hydrogen component include compounds containing a nonionic group and / or an anionic group and / or a cationic group and an active hydrogen. Examples of the compound having a nonionic group and an active hydrogen include a compound having two or more active hydrogen atoms or two or more isocyanate groups and having a polyoxyethylene glycol group or the like having a molecular weight of 250 to 9000 in the side chain and a compound having a polyoxyethylene group such as trimethylolpropane or trimethyl And triol such as butane and the like.

Examples of the compound having an anionic group and active hydrogen include compounds containing a carboxyl group such as 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolvaleric acid and their derivatives, 1,3-phenyl Compounds containing sulfonic acid groups such as lanediamine-4,6-disulfonic acid and 3- (2,3-dihydroxypropoxy) -1-propanesulfonic acid, and derivatives thereof, and salts obtained by neutralizing these compounds with a neutralizing agent .

Examples of the compound containing a cationic group and an active hydrogen include tertiary amino group-containing compounds such as 3-dimethylaminopropanol, N-methyldiethanolamine and N-propyldiethanolamine, and derivatives thereof.

The hydrophilic group-containing active hydrogen component can also be used in the form of a salt neutralized with a neutralizing agent.

From the viewpoints of the mechanical strength and the dispersion stability of the polyurethane resin, it is preferable to use 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid and neutralized salts thereof in the hydrophilic group-containing active hydrogen component used in the polyurethane molecule Do.

In addition to increasing the hydrophilicity of the polyurethane molecule by introducing hydroxyl group, sulfonic acid group and carboxyl group among the above-mentioned hydrophilic group-containing active hydrogen components into the polyurethane, a polyurethane molecule is given a three-dimensional crosslinked structure by using a cross- It is preferable that the hydrophilic group-containing active hydrogen component is appropriately selected and used.

As the make-up agent, a compound used in the conventional production of polyurethane can be used. Of these, a low molecular weight compound having a molecular weight of 600 or less and having at least two active hydrogen atoms in the molecule capable of reacting with an isocyanate group is preferably used. Specific examples of the solvent include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,4- , Triols such as trimethylol propane and trimethylol butane, and triols such as hydrazine, ethylenediamine, isophoronediamine, piperazine, 4,4'-methylenedianiline, tolylene diamine, xylylenediamine, hexamethylene Diamines such as 4,4'-dicyclohexylmethanediamine, triamines such as diethylenetriamine, aminoalcohols such as aminoethyl alcohol and aminopropyl alcohol, and the like.

Examples of the organic polyisocyanate include aliphatic diisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate (hereinafter may be abbreviated as IPDI), hydrogenated xylylene diisocyanate, dicyclohexylmethane diisocyanate (hereinafter referred to as hydrogen Alicyclic diisocyanate such as xylylene diisocyanate (hereinafter, may be abbreviated as XDI), tetramethyl-m-xylylene diisocyanate, etc., or an alicyclic diisocyanate such as xylylene diisocyanate , Tolylene diisocyanate (hereinafter may be abbreviated as TDI), 4,4'-diphenylmethane diisocyanate (hereinafter may be abbreviated as MDI), tolylidine diisocyanate and naphthalene diisocyanate (hereinafter referred to as NDI And an aromatic diisocyanate such as a diisocyanate (sometimes abbreviated).

By introducing a sulfonic acid group, a carboxyl group, a hydroxyl group, or a primary or secondary amino group into the polyurethane used in the present invention and incorporating a crosslinking agent having reactivity with these functional groups in the polyurethane dispersion, Also, the crosslinking density of the resin increases. As a result, the durability, weather resistance, heat resistance, and strength retention at the time of wetting can be further improved.

As the crosslinking agent, a crosslinking agent having two or more reactive groups capable of reacting with the reactive groups introduced into the polyurethane can be used. Specifically, crosslinking agents such as a polyisocyanate crosslinking agent such as a water-soluble isocyanate compound and a block isocyanate compound, a melamine crosslinking agent, an oxazoline crosslinking agent, a carbodiimide crosslinking agent, an aziridine crosslinking agent, an epoxy crosslinking agent and a hydrazine crosslinking agent . The crosslinking agent may be used alone or in combination of two or more.

The water-soluble isocyanate compound is a compound having two or more isocyanate groups in the molecule, and the organic polyisocyanate-containing compound. Commercially available products include "Baihidur" (registered trademark) series and "Death All" (registered trademark) series manufactured by Bayer MaterialScience.

The block isocyanate compound has two or more block isocyanate groups in the molecule. The block isocyanate group means that the organic polyisocyanate compound is blocked with blocking agents such as alcohols, amines, phenols, imines, mercaptans, pyrazoles, oximes, and active methylenes. As the commercially available products thereof, "Elastron" (registered trademark) series of Daiichi Kogyo Seiyaku Co., Ltd., "Dyuranate" (registered trademark) series of Asahi Kasei Chemicals Co., Ltd., and Mitsui Chemicals, "Takenate " (registered trademark) series of "

Examples of the melamine-based crosslinking agent include compounds having two or more methylol groups or methoxymethylol groups in the molecule. Commercially available products include "Ubane" (registered trademark) series manufactured by Mitsui Chemicals, Inc., "Cymel" (registered trademark) series manufactured by Nippon Cytec Co., Ltd., and "Sumi" manufactured by Sumitomo Chemical Co., (Registered trademark) series.

Examples of the oxazoline crosslinking agent include compounds having two or more oxazoline groups (oxazoline skeletons) in the molecule. Commercially available products include "Epochros" (registered trademark) series manufactured by Nippon Shokubai Co., Ltd. Examples of the carbodiimide-based crosslinking agent include compounds having two or more carbodiimide groups in the molecule. As a commercially available product thereof, a "carbodelite " (registered trademark) series manufactured by Nisshin Bossey K.K.

Examples of the epoxy cross-linking agent include compounds having two or more epoxy groups in the molecule. Examples of commercially available products include "Denacol" (registered trademark) series manufactured by Nagase Chemtech, diepoxy polyepoxy compounds manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., and "EPICRON" (registered trademark) series manufactured by DIC Corporation .

Examples of the aziridine crosslinking agent include compounds having two or more aziridinyl groups in the molecule. Examples of the hydrazine type crosslinking agent include hydrazine and a compound having two or more hydrazine groups (hydrazine skeleton) in the molecule.

Among them, preferred as the functional group of the polyurethane is a hydroxyl group and / or a carboxyl group and / or a sulfonic acid group, and preferable examples of the crosslinking agent are a polyisocyanate crosslinking agent and a carbodiimide compound. Further, by using a carbodiimide compound in combination with a polyisocyanate-based cross-linking agent, the cross-linking structure of the polyurethane resin can be further increased, and the effect of heat and humidity retention can be enhanced while maintaining flexibility.

Since the water-dispersible polyurethane generally contains a hydrophilic group in its molecular structure, it has a high affinity with water molecules as compared with the conventional organic solvent-based polyurethane, and is likely to swell in a wet environment, so that the molecular structure of the polyurethane tends to be relaxed. In a wet environment, it tends to be difficult to maintain the high physical properties obtained at the time of drying. On the other hand, by applying the crosslinking agent, the anti-wet heat effect is enhanced, and the tensile strength of the sheet during wetting can be increased. As a result, it is possible to suppress the structural change of the polyurethane molecule due to water in the dyeing step or the like, and to maintain the shape stability of the sheet product and the adhesion of the polyurethane and the fibrous substrate, We can attain decency.

Since the carbodiimide crosslinking agent has excellent crosslinking reactivity even at a low temperature of 100 占 폚 or lower, it is preferably used in terms of productivity. In addition, the isocyanate compound and / or the block isocyanate compound reacts mainly with the hydroxyl group, and at a temperature of not less than 120 ° C and not more than 200 ° C, preferably not less than 140 ° C and not more than 200 ° C, The reactivity with the urethane bond and / or the urea bond constituting the (HS) moiety is enhanced to form an allophanate bond or a biuret bond to give a stronger cross-linking structure, thereby making it possible to clarify the micro-phase separation structure of the polyurethane.

The storage elastic modulus E 'of the polyurethane film in the present invention at a temperature of 20 캜 is preferably 1 to 100 MPa, more preferably 2 to 50 MPa, from the viewpoints of flexibility and rebound resilience. The loss elastic modulus is preferably 0.1 MPa to 20 MPa, and more preferably 0.5 MPa to 12 MPa. The tan? Is preferably 0.01 to 0.4, more preferably 0.02 to 0.35.

The storage elastic modulus E 'and tan delta in the present invention were measured with a storage elastic modulus measuring device [DMA7100 (manufactured by Hitachi High-Tech Science Co., Ltd.)] with respect to a polyurethane film (film) Measured in Hz. tan? is a numerical value represented by E "/ E '(E" represents the loss elastic modulus).

Also, E 'represents the elastic property of the polyurethane resin. If this E' is too small, the folded wrinkle recovery property of the sheet-like material becomes insufficient. If it is excessively large, the feeling of the sheet-like material becomes hard.

On the other hand, tan < / RTI > represented by E "/ E '(where E" represents a loss elastic modulus and exhibits viscous properties) means a ratio of viscous properties based on elastic properties of polyurethane. If the tan delta is too small, the folded wrinkle recovery property of the sheet material becomes insufficient as in the case of E '. If the tan delta is excessively large, the skin feeling on the sheet becomes hard.

The density of the sheet material of the present invention is preferably 0.2 to 0.7 g / cm 3. The density is more preferably 0.2 g / cm 3 or more, and still more preferably 0.25 g / cm 3 or more. By setting the density to 0.2 g / cm 3 or more, the surface appearance becomes dense and a high quality can be expressed. On the other hand, when the density of the sheet-like material is preferably 0.7 g / cm 3 or less, and more preferably 0.6 g / cm 3 or less, it is possible to prevent the feel of the sheet-like material from becoming hard.

The proportion of the polyurethane contained in the sheet product of the present invention is preferably 10 to 80% by mass. By setting the ratio of the polyurethane to 10% by mass or more, more preferably 15% by mass or more, it is possible to prevent the fiber from falling off while obtaining the sheet strength. By setting the ratio of the polyurethane to 80 mass% or less, more preferably 70 mass% or less, it is possible to prevent the feeling of hardness from becoming hard and to obtain a satisfactory noodle quality.

The sheet product of the present invention can be obtained by applying an elastic polymer such as an aqueous dispersion type polyurethane and coagulating a liquid in which an aqueous dispersion of the aqueous dispersion type polyurethane or the like is used in combination with a thickener in hot water to form a porous structure of an aqueous dispersion type polyurethane So that excellent folded wrinkle recovery and flexibility, which is very similar to artificial leather to which a solvent-based polyurethane is applied, can be obtained.

That is, the sheet product of the present invention is a sheet product obtained by imparting a polymeric elastomer having a hydrophilic group as a binder to a fibrous base material comprising microfine fibers and / or ultrafine fiber bundles, , Wherein the occupation ratio of a portion having a cross-sectional area of at least 50 mu m ² independently of the polymeric elastic body observed in the cut surface is not less than 0.1% and not more than 5.0% with respect to the area of the cross section of the artificial leather in the observation visual field.

According to a preferred embodiment of the present invention, there is provided a sheet product obtained by imparting a polymeric elastomer having a hydrophilic group as a binder to a fibrous base material comprising microfine fibers and / or microfine fiber bundles, wherein in cross section cut in the thickness direction of the sheetfat, Wherein at least 1% and not more than 35% of the outer periphery of the cross section of the fiber and / or microfine fiber bundle is covered with the polymeric elastomer coating.

[Production method of sheet product]

Next, the method for producing the sheet material of the present invention will be described.

As the fibrous substrate used in the present invention, a fabric such as a fabric, a knitted fabric, and a nonwoven fabric can be preferably employed as described above. Among them, a nonwoven fabric is preferably used because the surface quality of the sheet is good when the surface is brushed. In the fibrous substrate of the present invention, these woven fabrics, knitted fabrics and nonwoven fabrics can be appropriately laminated and used in combination.

The nonwoven fabric to be used in the present invention may be any one of a short-fiber nonwoven fabric and a long-fiber nonwoven fabric, but a short-fiber nonwoven fabric is preferably used because a surface quality of uniform bristle length can be obtained.

The fiber length of the short fibers in the single-fiber nonwoven fabric is preferably 25 mm to 90 mm, and more preferably 35 mm to 75 mm. By setting the fiber length to 25 mm or more, a sheet product excellent in abrasion resistance can be obtained by entanglement. Further, when the fiber length is 90 mm or less, a sheet product having superior quality can be obtained.

Examples of the fiber constituting the fibrous substrate include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate and polylactic acid, polyamides such as 6-nylon and 66-nylon, acryl, polyethylene, A fiber including a melt-spinnable thermoplastic resin such as thermoplastic cellulose can be used. Among them, polyester fibers are preferably used from the viewpoints of strength, dimensional stability and light fastness. Further, the fibrous substrate may be composed of fibers of different materials mixed.

The cross-sectional shape of the fiber used in the present invention may be a circular cross-section, but may be a polygonal shape such as an ellipse, a flat or triangular shape, a cross-sectional shape such as a fan shape and a cross shape.

The average fiber diameter of the fibers constituting the fibrous substrate is preferably 0.1 to 7 mu m, more preferably 0.3 to 5 mu m. By making the average fiber diameter of the fibers 7 mu m or less, the feel of the fibrous substrate becomes more flexible. On the other hand, by setting the average fiber diameter of the fibers to 0.1 mu m or more, the coloring property after dyeing is further excellent.

In the present invention, in the case where the fibrous substrate is a nonwoven fabric, a fabric or knitted fabric can be combined with the nonwoven fabric for the purpose of improving the strength or the like. The combination of the nonwoven fabric and the fabric or the knitted fabric can be either of laminating the fabric or the knitted fabric to the nonwoven fabric, and inserting the fabric or knitted fabric into the nonwoven fabric. Above all, it is a preferable form to use a fabric from the viewpoint of improvement in form stability and strength improvement.

Examples of the single yarns (warp yarns and weft yarns) constituting the fabric or the knitted fabric include single yarns including synthetic fibers such as polyester fibers and polyamide fibers. From the standpoint of dyeing fastness, however, ultrafine fibers It is preferably a yarn comprising fibers of the same material as the fibers.

As the form of this single yarn, filament yarn and spun yarn can be mentioned, but preferably these yarns are used. Also, the filament yarn is preferably used in that the yarn is caused to fall off the surface fuzz.

When a strong yarn is used, the softened water is preferably not less than 1000 T / m and not more than 4000 T / m, more preferably not less than 1500 T / m and not more than 3500 T / m. When the number of years is less than 1000 T / m, the number of short staple fibers constituting the stiff yarn by the needle punching process increases, and the physical properties of the product and the tendency that the short fibers are exposed to the product surface tend to increase. Also, if the softening water is larger than 4000 T / m, the short-fiber slice is suppressed, but the hard yarn constituting the fabric or the knitted fabric tends to cause hardening of the tactile feeling because it becomes too hard.

Further, in the present invention, it is a preferable form to use microfine fiber-forming fibers in the fibrous substrate. By using the microfine fiber-forming fibers in the fibrous base material, it is possible to stably obtain a bundle of the above microfine fibers intertwined.

When the fibrous substrate is a nonwoven fabric, the nonwoven fabric preferably has a structure in which bundles (fiber bundles) of microfine fibers are entangled. The superfine fibers are entangled in a bundle state to improve the strength of the sheet. This type of nonwoven fabric can be obtained by preliminarily entangling the ultrafine fiber-forming fibers and then expressing the ultrafine fibers.

As the ultrafine fiber-expressible fiber, a two-component thermoplastic resin having a different solvent solubility is used as a sea component and an island component, and the sea component is dissolved and removed by using a solvent, (Sea-island) type composite fibers, and peelable composite fibers in which two component thermoplastic resins are alternately arranged in a radial or multilayered form on the fiber cross section, and each component is separated and divided into ultra fine fibers .

Among them, the sea-island conjugate fiber is preferably used from the standpoint of the flexibility and feel of the sheet-shaped composite, because it can provide appropriate voids between island components, that is, microfine fibers, by removing sea components.

In the sea-island composite fiber, a sea-island composite fiber is used, and a sea-island composite fiber in which two components of the sea component and the island component are arranged and arranged is mixed and mixed fibers And the like. However, the sea-island composite fiber is preferably used because it can obtain ultra-fine fibers of uniform fineness and also obtains ultrafine fibers of sufficient length and contributes to the strength of the sheet.

The sea component of the sea-island composite fiber may be polyethylene, polypropylene, polystyrene, copolymerized polyester obtained by copolymerizing sodium sulfoisophthalic acid or polyethylene glycol, polylactic acid, polyvinyl alcohol, or the like. Among them, copolyester, polylactic acid and polyvinyl alcohol for hot water storage are preferably used, which are degradable without using an organic solvent and copolymerized with alkaline degradable sodium sulfoisophthalic acid, polyethylene glycol or the like.

The ratio of the sea component to the island component of the sea-island composite fiber is preferably 0.2 to 0.9, more preferably 0.3 to 0.8, in terms of the mass ratio of the island fibers to the sea-island composite fiber. By setting the mass ratio of the sea component and the island component to 0.2 or more, the removal rate of the sea component can be reduced and the productivity is further improved. Further, by setting the mass ratio to 0.9 or less, it is possible to improve the openability of the island fibers and prevent the island components from joining. The number of islands can be adjusted appropriately according to the custody design.

The long diameter of the short fibers of the ultrafine fiber-forming fibers such as sea-island complex fibers is preferably 5 to 80 탆, more preferably 10 to 50 탆. If the long diameter of the short fibers is less than 5 탆, the strength of the fibers is weak, and the short fiber stub tends to increase in the needle punching process and the like to be described later. If the long diameter of the short fibers is larger than 80 mu m, efficient entanglement can not be achieved in the needle punching process or the like.

Examples of the method for obtaining the nonwoven fabric as the fibrous base material used in the present invention include a method of entangling the fibrous web by needle punching treatment or water jet punching treatment, a spunbonding method, a meltblowing method, a paper making method, or the like . Among them, a method such as a needle punching process, a water jet punching process, or the like is preferably used in order to obtain the microfine fiber bundle as described above.

In order to integrate the nonwoven fabric used as the fibrous substrate and the fabric or the knitted fabric into a laminate, needle punching treatment, water jet punching treatment and the like are preferably used from the viewpoint of entanglement of the fibers. Among them, the needle punching process is preferably used from the viewpoint that the fibers can be oriented in the vertical direction of the fibrous substrate without being restricted by the sheet thickness.

In the needles used in the needle punching process, the number of barb is preferably 1 to 9. By making the number of bobs more than one, efficient fiber entanglement can be achieved. On the other hand, by setting the number of bobs to 9 or less, fiber damage can be suppressed. If the number of barb is larger than 9, the fiber damage becomes large, and the needle mark remains on the fibrous base material, resulting in poor appearance of the product.

When the nonwoven fabric is integrated with the fabric or the knitted fabric, the provision of the nonwoven fabric with a preliminary entanglement prevents the occurrence of wrinkles when the nonwoven fabric and the fabric or knitted fabric are united in the needle punching process, . In this way, when adopting a method of preliminarily entangling by the needle punching process, it is effective to carry out the punch density at 20 pcs / cm 2 or more. Preferably, the pre-entanglement is imparted at a punch density of at least 100 / cm 2, and more preferably, the pre-entanglement is imparted at a punch density of 300 / cm 2 to 1300 / cm 2.

The width of the nonwoven fabric leaves a space to be narrowed by the needle punching process at the time of entanglement with the fabric or the knitted fabric at the punch density of less than 20 pcs / cm < 2 > Wrinkles are generated on the surface of the fibrous substrate, and a smooth fibrous substrate may not be obtained. If the punch density of the preliminary entanglement is larger than 1300 pcs / cm 2, entanglement of the nonwoven fabric itself is excessively advanced in general, and movement space enough to form entanglement with the fibers constituting the fabric or the knitted fabric is reduced. It is disadvantageous to realize a disadvantageous structure in which a fabric or a knitted fabric is firmly entangled.

In the present invention, when the fibers are entangled by the needle punching process regardless of the presence or absence of the fabric or the knitted fabric, the punch density is preferably in the range of 300 to 6000 / cm2, more preferably in the range of 1000 / / Cm < 2 > is more preferable.

In the entanglement of the nonwoven fabric and the fabric or the knitted fabric, a fabric or a knitted fabric is laminated on one side or both sides of the nonwoven fabric, or a fabric or a knitted fabric is sandwiched between a plurality of nonwoven fabrics and entangled with each other by a needle punching process. .

In the case of performing the water jet punching process, it is preferable that the water is in a columnar flow state. More specifically, it is preferable to spray water at a pressure of 1 to 60 MPa from a nozzle having a diameter of 0.05 to 1.0 mm.

The apparent density of the nonwoven fabric containing the microfine fiber-generating fibers after the needle punching treatment or the water jet punching treatment is preferably 0.13 to 0.45 g / cm3, and more preferably 0.15 to 0.30 g / cm3. By setting the apparent density to 0.13 g / cm 3 or more, an artificial leather having sufficient shape stability and dimensional stability is obtained. On the other hand, by setting the apparent density to 0.45 g / cm 3 or less, a sufficient space for imparting the polymeric elastomer can be maintained.

The thickness of the fibrous substrate is preferably 0.3 mm or more and 6.0 mm or less, and more preferably 1.0 mm or more and 3.0 mm or less. If the thickness of the fibrous substrate is less than 0.3 mm, the shape stability of the sheet-like product may become insufficient. When the thickness is larger than 6.0 mm, needle breakage tends to occur frequently in the needle punching step.

From the viewpoint of densification, the nonwoven fabric including the ultrafine fiber-generating fiber thus obtained can be shrunk by dry heat or wet heat or both to make it more densified.

The sea-island treatment for removing the sea component of the sea-island conjugate fiber in the case of using the sea-island conjugate fiber is preferably carried out before and / or after imparting the water-dispersible polyurethane dispersion containing the water- You can do it later. When the water-dispersible polyurethane dispersion solution is subjected to a deaeration treatment, the structure in which the polyurethane adheres directly to the superfine fiber tends to be formed, so that the superfine fiber can be firmly gripped, so that the abrasion resistance of the sheet is improved.

On the other hand, before applying the aqueous dispersion type polyurethane dispersion liquid, an aqueous dispersion type polyurethane dispersion liquid is added after imparting an inhibitor such as microfine fibers and a cellulose derivative or polyvinyl alcohol (hereinafter may be abbreviated as PVA), and the ultrafine fiber and the polyurethane resin It is possible to lower the adhesiveness of the base material and achieve a more flexible feel.

The inhibitor can be given at any time before or after the fiber de-ionization treatment of sea-island structure. By imparting an inhibitor before the deasphalting treatment, the shape retention of the fibrous substrate can be enhanced even when the weight per unit area of the fiber is lowered and the tensile strength of the sheet is lowered. As a result, not only a thin sheet can be stably processed, but also the thickness retention ratio of the fibrous substrate in the deasphalting step can be increased, and the density of the fibrous substrate can be suppressed. On the other hand, since it is possible to realize the high density of the fibrous substrate by performing the above-mentioned inhibitor application after the deaeration treatment, it is a preferable form to suitably adjust according to the purpose.

As the inhibitor, PVA is preferably used because it has high reinforcing effect on the fibrous substrate and is difficult to elute in water. Among the PVA, from the viewpoint that it is difficult to elute the inhibitor during the application of the aqueous dispersion type polyurethane dispersion and further the adhesion between the ultrafine fibers and the polyurethane can be inhibited, a high saponification degree PVA which is more water- It is a more preferable form to apply.

The degree of saponification of the high saponification degree PVA is preferably 95% or more and 100% or less, and more preferably 98% or more and 100% or less. When the saponification degree is 95% or more, elution at the time of imparting the aqueous dispersion type polyurethane dispersion can be suppressed.

The degree of polymerization of PVA is preferably 500 or more and 3500 or less, and more preferably 500 or more and 2,000 or less. When the polymerization degree of PVA is 500 or more, high saponification degree at the time of imparting the polyurethane dispersion can be inhibited from elution of PVA. Further, by setting the degree of polymerization of PVA to 3500 or less, the viscosity of the high saponification degree PVA solution does not become excessively high, and high saponification degree PVA can be stably imparted to the fibrous substrate.

The applied amount of PVA is preferably 0.1% by mass to 80% by mass, more preferably 5% by mass or more and 60% by mass or less, based on the fibrous substrate remaining in the product. High saponification degree By imparting PVA in an amount of 0.1 mass% or more, it is possible to suppress the morphological stability effect in the deasphalting process and the adhesion of the microfine fibers and polyurethane. Also, by imparting high saponification degree of not more than 80% by mass of PVA, the adhesion between the ultrafine fibers and the polyurethane is not excessively lowered, the worn fibers become uniform, and a product having a uniform surface quality can be completed.

As a method of imparting the inhibitor to the fibrous substrate, a method of dissolving the inhibitor in water and impregnating the fibrous substrate with water and drying by heating is preferably used from the viewpoint that the inhibitor can be evenly applied. If the temperature is excessively low, the drying time becomes long. If the temperature is too high, the inhibitor is completely insolubilized and can not be dissolved and removed later. Therefore, it is preferable to dry at a temperature of 80 ° C or more and 180 ° C or less, more preferably 110 ° C or more and 160 ° C or less. The drying time is preferably from 1 minute to 30 minutes from the viewpoint of workability.

The dissolution removal treatment of the inhibitor may be carried out by immersing the fibrous base material to which the inhibitor has been added in a steam at a temperature of 100 ° C or higher and hot water at a temperature of 60 ° C or more and 100 ° C or lower and then mangling, It is preferable to dissolve and remove it.

The deasphalting treatment can be carried out by immersing and immersing a fibrous base material containing the sea-island composite fibers in a liquid. When the sea component is polyethylene, polypropylene or polystyrene, an organic solvent such as toluene or trichlorethylene may be used as the solvent for dissolving the sea component. When the sea component is a copolymer polyester or polylactic acid, an aqueous solution of sodium hydroxide An alkaline solution is used. In the case where the sea component is polyvinyl alcohol, hot water can be used.

Next, the polyurethane used as the polymeric elastomer in the present invention will be described.

When the polyurethane is dispersed in an aqueous medium as the particles, it is preferable to use the above-mentioned hydrophilic group-containing active hydrogen component as a constituent component of the polyurethane from the viewpoint of dispersion stability of the polyurethane, and it is more preferable to use a neutralized salt to be.

Examples of the neutralizing agent used in the neutralized salt of the compound having a hydrophilic group and an active hydrogen include amine compounds such as trimethylamine, triethylamine and triethanolamine, and hydroxides such as sodium hydroxide and potassium hydroxide.

The addition timing of the neutralizing agent used for the hydrophilic group-containing active hydrogen component is not particularly specified, such as before or after the polyurethane polymerization process or before or after the dispersion process in the aqueous medium, but from the viewpoint of stability in the aqueous dispersion of the polyurethane, It is preferable to add it before the process or during the dispersion process in an aqueous medium.

The content of the hydrophilic group-containing active hydrogen component and / or its salt based on the mass of the polyurethane is preferably from 0.005 to 30 mass%, more preferably from 0.01 to 15 mass%, from the viewpoint of dispersion stability and water resistance of the polyurethane .

When the polyurethane is dispersed in an aqueous medium as the particles, the polyurethane can be dispersed in an aqueous medium using a surfactant as an external emulsifier of the polyurethane, in addition to using the active hydrogen-containing component containing the hydrophilic group.

Examples of such surfactants include nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants. The surfactant may be used alone, or two or more surfactants may be used in combination.

Examples of the nonionic surfactant include alkylene oxide addition type such as polyoxyethylene nonylphenyl ether, polyoxyethylene dinonylphenyl ether, polyoxyethylene lauryl ether and polyoxyethylene stearyl ether, polyhydric alcohol type such as glycerin monostearate And the like.

Examples of the anionic surfactant include carboxylic acid salts, sulfuric acid ester salts, sulfonic acid salts and phosphoric acid ester salts such as sodium laurate, sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate and sodium diisostearate, .

Examples of the cationic surfactant include quaternary ammonium salts such as distearyldimethylammonium chloride and the like. Examples of the amphoteric surfactant include methyl laurylaminopropionate, lauryldimethylbetaine and palm oil fatty acid amidepropyldimethylaminoacetate betaine.

As the dispersion of the polyurethane used in the present invention, a conventional method for producing a polyurethane dispersion can be applied. For example, a method in which a liquid state polymer obtained by reacting the above-mentioned polyisocyanate, polyol, make-up agent and / or hydrophilic group-containing polyol is emulsified in water in the presence of an emulsifier, or a method in which a polyisocyanate, a polyol and / Or a method in which a prepolymer having an isocyanate group at the molecular end reacted with a hydrophilic group-containing polyol is prepared, the prepolymer is emulsified in water in the presence of an emulsifier, and / or the completion of the elongation reaction is performed later with a make- Isocyanate, polyol and / or chain-extending agent and / or hydrophilic group-containing polyol is emulsified in water without using an emulsifier. When the polymerization is carried out without forming the prepolymer and when the prepolymer is polymerized, the polymerization may be carried out without solvent or in an organic solvent such as methyl ethyl ketone, toluene and acetone.

The polyurethane is applied to the fibrous base material by immersing the aqueous dispersed polyurethane dispersion containing the synthesized aqueous dispersion type polyurethane described above into the fibrous base material and then solidified by heating and drying to solidify the fibrous base material.

In the present invention, an aqueous dispersed polyurethane dispersion to which the above-mentioned thickening agent is added is added to the fibrous base material, and the water-dispersible polyurethane dispersion is dispersed in hot water at a temperature of preferably from 50 캜 to 100 캜, more preferably from 60 캜 to 97 캜 By coagulating the urethane, the porous structure of the polyurethane can be achieved.

The immersion time in the hot water is preferably from 10 seconds to 5 minutes, more preferably from 30 seconds to 3 minutes. By doing so, the polyurethane can be sufficiently solidified.

Since the coagulation method of the polyurethane is heat-set coagulation, the amount of heat applied to the polyurethane increases per unit of time, so that the coagulation speed becomes high and the dispersion of the aqueous dispersion of the polyurethane dispersion on the fibrous substrate becomes small. The adhesion is reduced and the feel is softened.

Also, by using a thickener in combination with the aqueous dispersion type polyurethane dispersion, the polyurethane emulsion in the aqueous dispersion type polyurethane dispersion impregnated in the fibrous base material is suppressed in Brownian motion of the emulsion due to the viscosity of the liquid. Therefore, the number of times of contact between the emulsions is reduced, the mass of polyurethane at the time of solidification can be reduced, and a flexible feeling can be achieved. In addition, since the dispersion liquid does not diffuse into the hot water, the dropout of the polyurethane during the coagulation step can be suppressed, and a solidification process with excellent productivity can be achieved.

The dispersion of water dispersion type polyurethane or other aqueous dispersion, in which a thickener is used in combination, is coagulated in hot water, so that the coating of the water-dispersible polyurethane (elastomer) is reduced and a soft texture is obtained. Further, the polyurethane coating film covering the fibrous base material is reduced, resulting in a soft texture.

As the thickening agent to be added to the aqueous dispersion type polyurethane dispersion, nonionic, anionic, cationic, and bionic ionic thickeners can be applied. Among them, a nonionic thickener is preferably used.

As the type of the thickener, it is possible to select from a combination type thickening agent and a water-soluble polymer type thickening agent. As the associative thickener, associative thickener known for a urethane-modified compound, an acrylic-modified compound and a copolymer compound thereof can be applied. For example, Japanese Patent Application Laid-Open Nos. 2003-292937, 2001-254068, 60-49022, 2008-231421, 2002-069430 Urethane-based associative thickener described in JP-A-9-71766, JP-A-62-292879 and JP-A-10-121030, And a associative thickener obtained by copolymerization with a maleic monomer.

Examples of the water-soluble polymer compound include natural polymer compounds, semi-synthetic polymer compounds and synthetic polymer compounds.

Examples of natural macromolecular compounds include nonionic compounds such as tamarind gum, guar gum, locust bean gum, tragacanth gum, starch, dextrin, gelatin, agarose, casein and curdlan, and xanthan gum, carrageenan, Anionic compounds such as gum, pectin, collagen, sodium chondroitin sulfate, sodium hyaluronate, carboxymethyl starch and phosphoric acid starch, and cationic compounds such as cationic starch and chitosan.

Examples of the semisynthetic polymer compound include nonionic compounds such as methylcellulose, ethylcellulose, hydroxyethylcellulose, ethylhydroxyethylcellulose, methylhydroxypropylcellulose, soluble starch and methyl starch, carboxymethylcellulose, carboxymethyl starch and alginic acid And an anionic compound such as a salt.

Examples of the synthetic polymer compound include nonionic compounds such as polyvinyl alcohol, polyacrylamide, polyvinyl pyrrolidone, polymethyl vinyl ether, polyethylene glycol and polyisopropylacrylamide, and carboxyvinyl polymer, sodium polyacrylate and polystyrene Sulfonic acid and sodium sulfonate, and cationic compounds such as quaternary salt of dimethylaminoethyl (meth) acrylate, dimethyldiallylammonium chloride, polyamidine, polyvinylimidazoline, and polyethyleneimine.

In the present invention, as the thickening agent, it is preferable to apply a nonionic thickener which hardly affects the stability of the aqueous dispersion type polyurethane dispersion liquid.

The aqueous dispersion type polyurethane dispersion to which a thickening agent is added preferably exhibits non-Newtonian properties. If the aqueous dispersion type polyurethane dispersion liquid has a property of lowering the viscosity due to the application of force among the non-new properties, the viscosity can be lowered by applying a force by stirring or the like, so that the dispersion can be uniformly impregnated in the fibrous base material, The viscosity is returned to the original value, so that the dispersion liquid impregnated in the fibrous substrate becomes difficult to detach from the fibrous substrate.

Further, the aqueous dispersion type polyurethane dispersion to which a thickening agent is added preferably exhibits thixotropic properties. If the aqueous dispersion type polyurethane dispersion is thixotropic, the viscosity is lowered by applying a force by stirring or the like, so that the dispersion can be uniformly impregnated in the fibrous base material, and after the application of the force, the viscosity is returned to the original value The dispersion liquid impregnated in the fibrous substrate becomes difficult to detach from the fibrous substrate.

As the thickening agent showing thixotropic property, a natural polymer compound (polysaccharide) which can be appropriately selected from the above-mentioned thickening agent but is expected to have a large thickening effect with a small addition amount is preferably used. As the thickening agent, guar gum is more preferable because of its excellent water solubility and compatibility with the aqueous dispersion type polyurethane liquid and high thixotropic property at a low concentration.

The viscosity of the aqueous resin dispersion containing the thickener is preferably from 200 mPa · s to 100000 mPa · s, more preferably from 200 mPa · s to 10000 mPa · s, even more preferably from 200 mPa · s to 5000 mPa · S. By setting the viscosity of the aqueous resin dispersion to 200 mPa · s or more, it is possible to suppress dropout of polyurethane in the hot water coagulation step and to set the viscosity to 100000 mPa · s or less, It can be uniformly impregnated.

From the viewpoint of suppressing the migration of the polyurethane during solidification of the polyurethane and uniformly impregnating the polyurethane into the fibrous substrate, it is preferable that the water dispersion type polyurethane dispersion imparted to the fibrous base material contains a heat coagulant.

Examples of the heat coagulant include inorganic salts such as sodium sulfate, magnesium sulfate, calcium sulfate, calcium chloride, magnesium chloride and calcium chloride, and ammonium salts such as sodium persulfate, potassium persulfate, ammonium persulfate and ammonium sulfate. It is possible to coagulate the water-dispersible polyurethane dispersion by heating and destabilizing the aqueous dispersion type polyurethane dispersion after adjusting the coagulation temperature of the water-dispersible polyurethane by adjusting the addition amount thereof either singly or in combination of two or more.

The thermal coagulation temperature of the aqueous dispersion type polyurethane dispersion is preferably from 40 to 90 캜, more preferably from 50 to 80 캜, from the viewpoints of storage stability and feeling of the fiber product after processing.

In addition to the above-mentioned crosslinking agent and thermosetting coagulant, the following various additives and the like may further be added to the polyurethane dispersion.

For example, pigments such as carbon black, antioxidants (antioxidants such as hindered phenol compounds, sulfur compounds and phosphorus compounds), ultraviolet absorbers (such as benzotriazole compounds, triazine compounds, benzophenone compounds and benzoate ultraviolet absorbers) (A water repellent agent such as a fluorine compound such as a silicone compound such as a polysiloxane or a modified silicone oil and a fluoroalkyl ester polymer of acrylic acid), a humectant (e.g., ethylene glycol, diethylene glycol (Wetting agents such as propylene glycol and glycerin), antifoaming agents (antifoaming agents such as octyl alcohol, sorbitan monooleate, polydimethylsiloxane, polyether modified silicone and fluorine denatured silicone), fillers (calcium carbonate, titanium oxide, silica, talc, Fine particles of ceramics, resin and the like and fillers such as hollow beads), flame retardants (halogen-based, phosphorus-based, antimony-based, melamine-based, guanidine- (For example, silicon-based and inorganic flame retardants such as guanyl urea compounds, etc.), microballoons (such as Matsumoto Microsphere 占 manufactured by Matsumoto), blowing agents such as dinitrosopentamethylenetetramine (For example, " Cell Mike A "(registered trademark) manufactured by Sankyo Kasei Co., Ltd.), azodicarbonamide (e.g., Based cellulosic blowing agents such as N-methyl-N, N'-dinitrosopentamethylenetetramine (e.g., "Cellular GX" (registered trademark) manufactured by EI WASEGAI) Azobis [2-methyl-N- (2-hydroxyethyl) propionamide], and the like), sodium hydrogen sulfate (e.g., an inorganic foaming agent such as " Cell Micro 266 " (E.g., "VA-086" manufactured by Wako Pure Chemical Industries, Ltd.), viscosity regulators, plasticizers (phthalic acid esters, adipic acid esters, etc.) It may contain additives such as (wax-based, metal soap-based release agents and the like in a mixed system).

It is preferable to further heat (cure) in order to accelerate fusion of the aqueous dispersion type polyurethane emulsion after the impregnation of the aqueous dispersion type polyurethane dispersion liquid to solidify the fibrous base material, to improve the molecular structure of the polyurethane, to be. The curing can be performed in succession to the step of impregnating the fibrous substrate with the aqueous dispersion of the polyurethane dispersion and then coagulating, or the water-dispersible polyurethane dispersion may be impregnated into the fibrous substrate to be coagulated, have.

If the temperature is excessively low, the drying time is required for a long period of time. If the temperature is too high, pyrolysis of the polyurethane is accelerated. Therefore, the drying temperature is preferably 80 ° C or more and 200 ° C or less, more preferably 120 ° C Or more and 190 占 폚 or less, and more preferably 150 占 폚 or more and 180 占 폚 or less.

The drying time is preferably from 1 minute to 60 minutes, more preferably from 1 minute to 30 minutes from the viewpoint of workability. In the present invention, by treating the cure temperature at a high temperature for a short time, the fluidity of the polyurethane molecules is improved, and the hard segment (HS) portion formed mainly from the urethane group and the urethane resin and the soft segment (SS) portion formed mainly from the polyol It is possible to clarify the micro phase separation structure of the HS and the SS part by increasing the aggregation of the HS part in the molecular structure including the molecular structure, and it is possible to improve the heat and humidity resistance.

After the polyurethane is applied, it is preferable to divide the sheet-like article having the obtained polyurethane into half to several sheets in the thickness direction of the sheet, since the production efficiency is excellent.

A lubricant such as a silicone emulsion may be added to the polyurethane-applied sheet product before the brushed process to be described later. In addition, the provision of the antistatic agent before the brushed treatment is a preferable form for making it difficult for the grinding particles generated from the sheet material to be deposited on the sandpaper by grinding.

A brushed process can be performed to form nap on the surface of the sheet. The brushed treatment can be carried out by a method of grinding using sandpaper or roll thunder.

If the thickness of the sheet is too thin, the physical properties such as tensile strength and tear strength of the sheet become weak. If the sheet is too thick, the thickness of the sheet is preferably 0.1 to 5.0 mm.

The sheet product can be dyed. As a dyeing method, it is preferable to use a liquid dyeing machine in that a sheet product is dyed and at the same time a rubbing effect is imparted to soften the sheet product. If the dyeing temperature is too high, the polyurethane may be deteriorated. On the other hand, if the dyeing temperature is excessively low, dyeing of the dye to the fiber becomes insufficient, so that the dyeing temperature can be set according to the type of the fiber. The dyeing temperature is generally 80 ° C or higher and 150 ° C or lower, and more preferably 110 ° C or higher and 130 ° C or lower.

The dye used is selected according to the type of fibers constituting the fibrous substrate. For example, if the polyester fiber is a disperse dye, the polyamide fiber may be an acid dye or a gold dye, or a combination thereof may be used. When the sheet is dyed with a disperse dye, reduction washing can be performed after dyeing.

It is also desirable to use a dyeing aid in dyeing. By using a dyeing aid, uniformity and reproducibility of dyeing can be improved. After dyeing, bathing or dyeing, a finishing agent treatment using a softener such as silicone, an antistatic agent, a water repellent agent, a flame retardant agent, an anti-light agent, and an antibacterial agent can be performed.

The sheet product obtained by the present invention is mainly used as an artificial leather and is used as a skin material such as furniture, a chair and a wall material, a seat, a ceiling and an interior in a vehicle interior such as an automobile, a train, Wearing cloths, polishing cloths and CD's used in bags, belts, wallets, etc., and some of them, such as shoes, jackets, casual shoes, sport shoes, shoe uppers and ladies shoes, And can be suitably used as an industrial material such as a curtain.

Example

Next, the sheet product of the present invention and the production method thereof will be described in more detail by way of examples, but the present invention is not limited to these examples.

[Assessment Methods]

(1) Drop-out rate at the time of solidification of polyurethane:

The mass of the fibrous substrate and the weight of the fibrous substrate after impregnating the aqueous dispersion of the polyurethane dispersion were measured, and the polyurethane solid content contained in the differential was determined as the polyurethane adhesion amount A. Next, the fibrous base material impregnated with the aqueous dispersion type polyurethane dispersion was coagulated with hot water or steam, and the mass after drying was measured to determine the difference with the fibrous base material as the polyurethane adhesion amount B. The polyurethane decolorization rate during solidification was calculated by the following formula, and the average of the results of 10-point measurement was evaluated.

Polyurethane dropout rate (%) = Polyurethane adhesion amount B / Polyurethane adhesion amount 100

(2) Viscosity measurement of aqueous dispersion polyurethane dispersion:

The viscosity of the prepared aqueous dispersion type polyurethane dispersion was measured using a rotational viscometer (B-type viscometer: Tokyo Keikyu Seisho Co., Ltd.) under the conditions of a rotational speed of 0.5 rpm and a rotational speed of 10 rpm Respectively.

(3) Exterior appearance of the sheet:

The appearance quality of the sheet material was evaluated by visual and sensory evaluation in five steps as follows, with 20 persons, each 10 healthy male and female female, as the evaluator, and the most evaluation was made as appearance quality. Appearance grade was good from grade 4 to grade 5.

Grade 5: There are uniform napping of fibers, good fiber dispersion and good appearance.

Level 4: An evaluation between level 5 and level 3.

Grade 3: There are some poorly dispersed fibers, but the fibers are napped and the appearance is good.

Level 2: An evaluation between level 3 and level 1.

Grade 1: Overall, the dispersion state of the fibers is very poor and appearance is poor.

(4) Tactile sensation on sheet:

The tactile sensation of the sheet was evaluated by sensory evaluation by tactile sensation in the following three stages by evaluating each of 10 healthy male and female female, 20 in total, as the evaluation of the tactile sensation. The touch was rated as good (excellent rubber elasticity).

⊚: It is more flexible than artificial leather applying organic solvent-based polyurethane having the same weight per unit area, and is excellent in crease recovery property.

○: Flexibility equivalent to that of artificial leather using organic solvent-based polyurethane having the same weight per unit area and folding wrinkle recovery.

X: The feeling of paper-like feeling due to the hardness of the sheet.

(5) Calculation method of occupation ratio of non-porous mass of 50 탆 ² or more (parameter A):

For 10 pieces of SEM images obtained by observing the cross section cut in the thickness direction of the artificial leather in the longitudinal direction or the width direction of the artificial leather with a scanning electron microscope (SEM) at a magnification of 500 times, The area of the section of the artificial leather section in the observation field (4.3 x 10 ⁴ 탆 ² ) of the SEM image area of a mass of 50 탆 ² or more in the section of the polyurethane observed from the section was analyzed by ImageJ (version: 1.44p) And the ratio was evaluated by an average value of the numerical values of the calculated 10 images. Fig. 3 shows a schematic diagram of the method for calculating the parameter A. Fig. Fig. 3 is a schematic view showing a lump 1 of polyurethane of the parameter A, and a lump 1 of a polyurethane refers to a polyurethane cross section (not including the inside portion from the end face) observed in the cross section of the artificial leather, Fig.

(6) Calculation method of polymer elastomer film ratio of cross section of ultrafine fiber (parameter B):

For 10 pieces of SEM images obtained by observing the cross section cut in the thickness direction of the artificial leather in the longitudinal direction or the width direction of the artificial leather with a scanning electron microscope (SEM) at a magnification of 500 times, With respect to five microfine fiber bundles observed in a state in which the microfine fiber bundles were cut vertically in the longitudinal direction of the fiber, ImageJ (version: 1.44p) as the image analysis software, resin having a thickness of 1 占 퐉 or more And the ratio of the portion in contact with the coating film was calculated. The evaluation was made by the average value of the polymer elastomer film ratios of 50 microfine fiber cross sections of 5 x 10 images calculated. Fig. 4 shows a schematic diagram of the parameter B calculation method. 4 is a schematic view showing the outer periphery 2 of the microfine fiber bundle and / or the microfine fiber bundle of parameter B and the outer periphery 3 covered by the polymer elastomer coating. The solid line part shows the outer periphery 2 of the microfine fiber bundle, And the outer periphery 3 covered with the polymeric elastomer coating.

[Preparation of polyurethane liquid A]

Polycarbonate diol having a Mn of 2,000 in a polyol ("Dylanol (registered trademark) T5652" manufactured by Asahi Kasei Chemicals Co., Ltd.), MDI as an isocyanate, 2,2-dimethylolpropionic acid as a hydrophilic group in the molecule After preparing a prepolymer in a toluene solvent, ethylene glycol and ethylenediamine as a shortening agent and polyoxyethylene nonylphenyl ether and water as an external emulsifier were added and stirred. Thereafter, toluene was removed under reduced pressure to obtain a water-dispersible polyurethane Thereby obtaining a dispersion A.

[Preparation of polyurethane liquid B]

Polycarbonate diol having a Mn of 2,000 in a polyol ("DURANOL (registered trademark) T6002" manufactured by Asahi Kasei Chemicals Co., Ltd.), IPDI in an isocyanate, and diol compound having a polyethylene glycol in a side chain as a hydrophilic group in the molecule And 2,2-dimethylolpropionic acid were used to prepare a prepolymer in an acetone solvent. Ethylene glycol, ethylenediamine and water were added as a chain extender, and the mixture was stirred. After that, acetone was removed under reduced pressure to obtain a water dispersion type polyurethane dispersion B .

[Preparation of polyurethane liquid C]

Polycarbonate diol having a Mn of 2,000 in a polyol ("Dylanol" (registered trademark) T5652, manufactured by Asahi Kasei Chemicals Co., Ltd.), IPDI in isocyanate and trimethylolpropane in the molecule as methyl ethyl After preparing a prepolymer in a ketone solvent, ethylene glycol and ethylenediamine as a shortening agent, polyoxyethylene nonylphenyl ether and water as an external emulsifier were added and stirred, and methyl ethyl ketone was removed under reduced pressure to obtain a water dispersion type polyurethane dispersion D.

[Example 1]

Polyethylene terephthalate copolymerized with 8 mol% of sodium 5-sulfoisophthalate as an ocean component and polyethylene terephthalate as an island component were mixed at a mixing ratio of 20 mass% of sea component and 80 mass% of island component , An island number of 16 islands / one filament, and an average fiber diameter of 20 占 퐉. The obtained sea-island composite fibers were cut into a staple with a fiber length of 51 mm, and a fibrous web was formed through a card and a cross wrapper to form a nonwoven fabric by needle punching.

The nonwoven fabric thus obtained was shrunk by immersing in hot water at a temperature of 97 캜 for 2 minutes and dried at a temperature of 100 캜 for 5 minutes. Subsequently, an active ingredient of a associative thickener ("Sikner 627N" manufactured by SANNOKO CO., LTD.) Was added to the obtained water-dispersible polyurethane dispersion A having a polyurethane solid content concentration adjusted to 20% %, And magnesium sulfate in an amount of 1.2% by mass based on the solid content of the polyurethane was impregnated, treated for 1 minute in hot water at 95 ° C, and then subjected to hot air drying for 15 minutes at a drying temperature of 100 ° C. Lt; 0 > C for 20 minutes.

To obtain a sheet to which an aqueous dispersion type polyurethane was applied so that the polyurethane mass with respect to the mass of the island component of the nonwoven fabric was 35 mass%. The drop of the polyurethane at the time of hydrothermal coagulation of the polyurethane was almost 0.1%.

Next, the sheet thus obtained was immersed in an aqueous solution of sodium hydroxide having a concentration of 10 g / L heated to a temperature of 95 캜 and treated for 25 minutes to obtain a deasphalted sheet from which marine components of sea-island complex fibers were removed. The average short fiber diameter of the short fibers on the surface of the obtained deasphalted sheet was 4.2 탆. Thereafter, the deaerated sheet was vertically folded in half in the thickness direction by using a half-period with a band knife of endless, and the side of the half-off side was ground by using sandpaper of 120 mesh and 240 mesh to perform brushed processing. Thereafter, the resultant was dyed with a disperse dye using a circular dyeing machine and subjected to reduction washing to obtain artificial leather having a weight per unit area of 221 g / m 2. The appearance of the obtained artificial leather was good and the feeling was good without feeling of paper-like feeling. Parameter A was 4.0% and parameter B was 27.1%.

[Example 2]

5 parts by mass of an active component of an epoxy crosslinking agent (" CR-5L ", manufactured by DIC Corporation) relative to the solid content of polyurethane was added to the above aqueous dispersion polyurethane dispersion liquid A in which the solid content concentration was adjusted to 20% 4% by mass of the active ingredient of polyurethane solid content and 1.2% by mass of magnesium sulfate relative to the polyurethane solid content) was impregnated in the same nonwoven fabric as in Example 1 (the "Sikner 627N" manufactured by NOVO CO., LTD. An artificial leather having a weight per unit area of 223 g / m 2 was obtained in the same manner as in Example 1. The dropout of the polyurethane during the hydrothermal solidification of the water-dispersible polyurethane was not substantially 0.1%. The appearance of the obtained artificial leather was good and the feeling was good without feeling of paper-like feeling. Parameter A was 4.1% and parameter B was 25.4%.

[Example 3]

Polyethylene terephthalate copolymerized with 8 mol% sodium 5-sulfoisophthalate as an ocean component was used and polyethylene terephthalate was used as an island component to obtain a composite mass ratio of 20 mass% of an ocean component and 80 mass% of an island component , And a sea-island composite fiber having an island number of 16 islands / 1 filament and an average fiber diameter of 20 mu m was obtained. The obtained sea-island composite fibers were cut into a staple with a fiber length of 51 mm, and a fibrous web was formed through a card and a cross wrapper to form a nonwoven fabric by needle punching.

The thus obtained nonwoven fabric was shrunk by immersing in hot water at a temperature of 97 캜 for 5 minutes and dried at a temperature of 100 캜 for 10 minutes. Next, an aqueous solution of PVA ("NM-14" manufactured by Nippon Gosei Chemical Industry Co., Ltd.) having a degree of saponification of 99% and a degree of polymerization of 1400 was adjusted with an aqueous solution having a solid content of 10% by mass was added to the obtained nonwoven fabric. At room temperature for 10 minutes, followed by further heating at a temperature of 150 DEG C for 20 minutes to obtain a sheet. Next, the thus obtained sheet was immersed in an aqueous solution of sodium hydroxide having a concentration of 100 g / L heated at a temperature of 50 占 폚 and treated for 20 minutes to obtain a deasphalted sheet from which marine components of the sea-island complex fiber were removed. The average fiber diameter of the short fibers on the surface of the obtained deasphalted sheet was 4.2 탆. Thereafter, the deasphalted sheet was impregnated with the aqueous dispersion type polyurethane dispersion A adjusted in the same manner as in Example 2, treated for 1 minute in hot water at 95 ° C, and then subjected to hot air drying at a drying temperature of 100 ° C for 15 minutes, To obtain a sheet to which an aqueous dispersion type polyurethane was applied so that the polyurethane mass with respect to the island component mass was 35 mass%. The sheet provided with the aqueous dispersion type polyurethane was immersed in hot water at a temperature of 98 캜 for 10 minutes to remove the applied PVA and then dried at a temperature of 100 캜 for 10 minutes. Thereafter, the obtained sheet was further heated at a temperature of 160 DEG C for 20 minutes.

Thereafter, the deaerated sheet was vertically halved in the thickness direction by using a half period with a band knife of endless, and the side not halved was grinded using a sandpaper of 120 mesh and 240 mesh and brushed, Was dyed with a disperse dye and subjected to reduction washing to obtain an artificial leather having a weight per unit area of 230 g / m 2. The drop of the polyurethane during the hydrothermal solidification of the water-dispersible polyurethane was not nearly 0.2%. The appearance of the obtained artificial leather was good and the feeling was good without feeling of paper-like feeling. Parameter A was 3.8% and parameter B was 20.3%.

[Example 4]

To the aqueous dispersion type polyurethane dispersion liquid B in which the solid content concentration was adjusted to 20%, a dispersion liquid in which 3% by mass relative to the polyurethane solid content of the active ingredient of the associative thickener ("Sikner 623N" manufactured by Sanobo Co., Ltd.) , An artificial leather having a weight per unit area of 218 g / m 2 was obtained in the same manner as in Example 1, except that the nonwoven fabric was impregnated with the same nonwoven fabric as in Example 1.

The dropout of the polyurethane during the hydrothermal solidification of the water-dispersible polyurethane was not substantially 0.1%. The appearance of the obtained artificial leather was good and the feeling was good without feeling of paper-like feeling. Parameter A was 4.0% and parameter B was 26.8%.

[Example 5]

To the aqueous dispersion type polyurethane dispersion liquid B in which the solid content concentration was adjusted to 20%, an aqueous solution of an active ingredient of aqueous isocyanate ("Des Allure" (registered trademark) N3900 "manufactured by Bayer Material Science Co., 3% by mass of an active ingredient of a carbodiimide type crosslinking agent ("Carbodilite (registered trademark) V-02-L2" manufactured by Nissinbo Chemical Co., Except that the dispersion was prepared by impregnating the same nonwoven fabric as that of Example 1 with a dispersion solution prepared by adding 3% by mass of an active ingredient of a thickener ("Sikner 623N" manufactured by Sanobo Co., Ltd.) to the polyurethane solid content, An artificial leather having an area weight of 220 g / m 2 was obtained.

The drop of the polyurethane during the hydrothermal solidification of the water-dispersible polyurethane was not nearly 0.2%. The appearance of the obtained artificial leather was good and the feeling was good without feeling of paper-like feeling. Parameter A was 4.3% and parameter B was 30.3%.

[Example 6]

To the aqueous dispersion type polyurethane dispersion liquid B in which the solid content concentration was adjusted to 20%, an aqueous solution of an active ingredient of aqueous isocyanate ("Des Allure" (registered trademark) N3900 "manufactured by Bayer Material Science Co., 3% by mass of an active ingredient of a carbodiimide type crosslinking agent ("Carbodilite (registered trademark) V-02-L2" manufactured by Nissinbo Chemical Co., Except that the dispersion in which the active ingredient of the thickener ("Sikner 623N" manufactured by Sanobo Co., Ltd.) was added in an amount of 3% by mass based on the polyurethane solid content was impregnated with the same nonwoven fabric as in Example 3, An artificial leather having an area weight of 220 g / m 2 was obtained.

The drop of the polyurethane during the hydrothermal solidification of the water-dispersible polyurethane was not nearly 0.2%. The appearance of the obtained artificial leather was good and the feeling was good without feeling of paper-like feeling. Parameter A was 4.2% and parameter B was 20.4%.

[Example 7]

After the fiber webs were formed through the card and the cross wrapper using the sea-island conjugated fiber of Example 1, and the obtained fiber webs were laminated, the continuous yarns each contained 84 dtex-72 filaments, 76 (light-weighted) was superimposed on the front and back of the laminated fibrous web, and then the laminated nonwoven fabric was made into a laminated nonwoven fabric by a needle punching process, and an aqueous dispersible nonwoven fabric having a polyurethane content of 28% A sheet obtained by grinding the surface of the half-cut side with sandpaper of 120 mesh and 240 mesh and brushed the sheet by half using a semi-circular machine having a band knife of endless, An artificial leather having a weight per unit area of 393 g / m 2 was obtained in the same manner as in Example 6. The drop of the polyurethane during the hydrothermal solidification of the water-dispersible polyurethane was not nearly 0.2%. The appearance of the obtained artificial leather was good and the feeling was good without feeling of paper-like feeling. Parameter A was 3.6% and parameter B was 20.1%.

[Example 8]

To the aqueous dispersion polyurethane dispersion A in which the solid content concentration was adjusted to 20%, an aqueous solution of an active ingredient of aqueous isocyanate ("Death All (registered trademark) N3900" manufactured by Bayer MaterialScience Co., %, An active ingredient of a carbodiimide type crosslinking agent ("Carbodilite (registered trademark) V-02-L2" manufactured by Nissinbo Chemical Co., Ltd.) in an amount of 3% by mass based on the polyurethane solid content, 2% by mass based on the solid content of the polyurethane and 1.2% by mass based on the polyurethane solid content of the active ingredient of the [Neo Soft G " manufactured by Daikogaku K.K.] were added to the same nonwoven fabric as in Example 3 The artificial leather having a weight per unit area of 221 g / m 2 was obtained in the same manner as in Example 3, except that the impregnated and impregnated polyurethane dispersion were treated in hot water at 95 ° C for 3 minutes.

The dropout of the polyurethane during the hydrothermal solidification of the water-dispersible polyurethane was not substantially 0.1%. In addition, the half-folded half-side had no uneven adhesion of polyurethane, and the fibrous base material was impregnated with uniform polyurethane. The appearance of the obtained artificial leather was good and the feeling was good without feeling of paper-like feeling. The parameter A was 3.3% and the parameter B was 18.9%.

[Example 9]

After the fiber webs were formed through the card and the cross wrapper using the sea-island conjugated fiber of Example 1, and the obtained fiber webs were laminated, the continuous yarns each contained 84 dtex-72 filaments, 76 (light-weighted) was superimposed on the front and back of the laminated fibrous web, and then the laminated nonwoven fabric was made into a laminated nonwoven fabric by a needle punching process, and an aqueous dispersible nonwoven fabric having a polyurethane content of 28% A sheet obtained by grinding the surface of the half-cut side with sandpaper of 120 mesh and 240 mesh and brushed the sheet by half using a semi-circular machine having a band knife of endless, An artificial leather having a weight per unit area of 390 g / m 2 was obtained in the same manner as in Example 8. The dropout of the polyurethane during the hydrothermal solidification of the water-dispersible polyurethane was not substantially 0.1%. In addition, the half-folded half-side had no uneven adhesion of polyurethane, and the fibrous base material was impregnated with uniform polyurethane. The appearance of the obtained artificial leather was good and the feeling was good without feeling of paper-like feeling. Parameter A was 2.9% and parameter B was 19.2%.

[Example 10]

Except that the nonwoven fabric was not subjected to the application and drying of PVA ("NM-14" manufactured by Nippon Gosei Chemical Industry Co., Ltd.) having a degree of saponification of 99% and a degree of polymerization of 1400, 388 g / m < 2 >. The dropout of the polyurethane during the hydrothermal solidification of the water-dispersible polyurethane was not substantially 0.1%. In addition, the half-folded half-side had no uneven adhesion of polyurethane, and the fibrous base material was impregnated with uniform polyurethane. The appearance of the obtained artificial leather was good and the feeling was good without feeling of paper-like feeling. The parameter A was 1.1% and the parameter B was 4.9%.

[Example 11]

To the aqueous dispersion type polyurethane dispersion liquid B in which the solid content concentration was adjusted to 20%, an aqueous solution of an active ingredient of aqueous isocyanate ("Des Allure (registered trademark) N3900" manufactured by Bayer Material Science Ltd.) % And a dispersion liquid obtained by adding 2.5% by mass of an active ingredient of a thickening polysaccharide guar gum ("Neosoft G" manufactured by Daiyo Kagaku Co., Ltd.) to the polyurethane solid content was impregnated into the nonwoven fabric in the same manner as in Example 9 , And an artificial leather having a weight per unit area of 388 g / m 2 was obtained.

The dropout of the polyurethane during the hydrothermal solidification of the water-dispersible polyurethane was not substantially 0.1%. In addition, the half-folded half-side had no uneven adhesion of polyurethane, and the fibrous base material was impregnated with uniform polyurethane. The appearance of the obtained artificial leather was good and the feeling was good without feeling of paper-like feeling. The parameter A was 2.5% and the parameter B was 14.3%.

[Example 12]

(Carbodilite 占 (registered trademark) V-02-L2, manufactured by Nisshinbo Chemical Co., Ltd.) as a crosslinking agent based on carbodiimide was added to the aqueous dispersion type polyurethane dispersion liquid C in which the solid content concentration was adjusted to 20% , 4 mass% of polyurethane solid content, 2 mass% of active ingredient of guar gum of thickening polysaccharide (" Neosoft G ", manufactured by Daiyo Kagaku Co., Ltd.) based on polyurethane solid content, and magnesium sulfate to polyurethane solid content An artificial leather having a weight per unit area of 386 g / m < 2 > was obtained in the same manner as in Example 9 except that the non-woven fabric was impregnated with the dispersion in which 3.0 mass%

The dropout of the polyurethane during the hydrothermal solidification of the water-dispersible polyurethane was not substantially 0.1%. In addition, the half-folded half-side had no uneven adhesion of polyurethane, and the fibrous base material was impregnated with uniform polyurethane. The appearance of the obtained artificial leather was good and the feeling was good without feeling of paper-like feeling. The parameter A was 1.2% and the parameter B was 5.2%.

[Example 13]

Except that the nonwoven fabric was not subjected to the application and drying of PVA ("NM-14" manufactured by Nippon Gosei Chemical Industry Co., Ltd.) having a degree of saponification of 99% and a degree of polymerization of 1400, 388 g / m < 2 >. The dropout of the polyurethane during the hydrothermal solidification of the water-dispersible polyurethane was not substantially 0.1%. In addition, the half-folded half-side had no uneven adhesion of polyurethane, and the fibrous base material was impregnated with uniform polyurethane. The appearance of the obtained artificial leather was good and the feeling was good without feeling of paper-like feeling. The parameter A was 0.7% and the parameter B was 4.0%.

Fig. 1 shows a cross section of the artificial leather obtained in Example 13. Fig. The state of the polyurethane and microfine fiber bundle observed in the cross section of Fig. 1 was such that the cross section of the polyurethane was small (the mass of the polyurethane was small) and the adhesion between the microfine fiber bundle and the polyurethane was small.

[Comparative Example 1]

The same procedure as in Example 1 was carried out except that a dispersion liquid in which 1.2 mass% of magnesium sulfate was added to the polyurethane solid content was impregnated into the same nonwoven fabric as that of Example 1 in the aqueous dispersion type polyurethane dispersion liquid A in which the solid content concentration was adjusted to 20% , And an artificial leather having a weight per unit area of 223 g / m 2 was obtained. The dropping of the polyurethane during the hydrothermal solidification of the water dispersible polyurethane was 22.1%, and the nonuniform adhesion of the polyurethane to the fibrous base material occurred.

[Comparative Example 2]

An artificial leather having a weight per unit area of 223 g / m 2 was obtained in the same manner as in Example 1 except that the aqueous dispersion polyurethane dispersion B in which the solid content concentration was adjusted to 20% was impregnated with the same nonwoven fabric as in Example 1. The dropout of polyurethane during the hot-solidification of the polyurethane was 15.1%, and the adhesion of the polyurethane to the fibrous base material was uneven.

[Comparative Example 3]

The aqueous dispersion of polyurethane dispersion B in which the solid content concentration was adjusted to 20% was impregnated in the same nonwoven fabric as in Example 1 and treated for 5 minutes in a humid atmosphere at a temperature of 97 DEG C and a humidity of 100% An artificial leather having a weight per unit area of 223 g / m 2 was obtained in the same manner as in Example 1, except that an aqueous dispersion type polyurethane resin was added so that the polyurethane mass with respect to the mass of the island component of the nonwoven fabric was 35 mass%. The dropout of the polyurethane during the water-solidification of the water-dispersible polyurethane was 0.0%, but the feel of the obtained artificial leather was strong in paper-like feeling. Parameter A was 7.9% and parameter B was 42.2%.

[Comparative Example 4]

The aqueous dispersion polyurethane dispersion B in which the solid content concentration was adjusted to 20% was impregnated in the same nonwoven fabric as in Example 13 and treated for 5 minutes in a humid atmosphere at a temperature of 97 DEG C and a humidity of 100% Dried to obtain an artificial leather having a weight per unit area of 389 g / m 2 in the same manner as in Example 13, except that an aqueous dispersion type polyurethane resin was added so that the polyurethane mass with respect to the mass of the island component of the nonwoven fabric was 28% by mass. The dropout of polyurethane during the hydrothermal solidification of the water-dispersible polyurethane was 0.0%, but the texture of the obtained artificial leather was strong in paper-like feeling. Parameter A was 8.1% and parameter B was 43.1%.

Fig. 2 shows a section of the artificial leather obtained in Comparative Example 4. Fig. The state of the polyurethane and the microfine fiber bundle observed in the cross section of Fig. 2 was in a good state because the cross-section of the polyurethane was large (large amount of the polyurethane) and the adhesion of the microfine fiber bundle and the polyurethane was large.

The results of Examples 1 to 7 and Comparative Examples 1 to 4 are summarized in Tables 1 and 2.

In the example, the numerical value of the parameter A is smaller than that of the comparative example, and therefore, the mass of the polyurethane is small, and the polyurethane is uniformly dispersed in the artificial leather. In addition, since the parameter B in the example is smaller than that in the comparative example, the adhesion between the microfine fiber bundle and the polyurethane is small, and a flexible texture is obtained.

1: Lump of polyurethane
2: Outline of microfiber bundle
3: Outer periphery covered with polymer elastomer film

Claims (12)

Wherein the polymeric elastomer having a hydrophilic group is imparted as a binder to a fibrous base material comprising a superfine fiber and / or a superfine fiber bundle, wherein in a cross section taken along the thickness direction of the sheet- Wherein the occupation ratio of a portion having a cross-sectional area of 50 占 퐉 ² or more is 0.1% or more and 5.0% or less with respect to the area of the cross section of the artificial leather in the observation field of view. The sheet member according to claim 1, wherein 1% or more and 35% or less of the outer periphery of the microfine fiber and / or the microfine fiber bundle cross-section is covered with the polymeric elastomer film on the cross section taken along the thickness direction of the sheet. The sheet member according to claim 1 or 2, wherein the polymeric elastomer has a structure crosslinked by a crosslinking agent. A method for producing a sheet-like product in which a polymeric elastomer having a hydrophilic group is imparted as a binder to a fibrous base material containing microfine fibers, the aqueous resin dispersion comprising a polymeric elastomer dispersed in water and a thickening agent is added to the fibrous base material, Wherein said polymeric elastomer is solidified in hot water at a temperature of 100 to < RTI ID = 0.0 > 100 C. < / RTI > 5. The method of producing a sheet material according to claim 4, wherein the aqueous resin dispersion exhibits a non-Newtonian property. The sheet-like water producing method according to claim 4 or 5, wherein the thickener is a nonionic thickener. The sheet-like water producing method according to any one of claims 4 to 6, wherein the aqueous resin dispersion has a thixotropic property. The sheet-like water producing method according to any one of claims 4 to 7, wherein the thickening agent is a thickening polysaccharide. 9. The process according to any one of claims 4 to 8, wherein the thickener is guar gum. 10. The process for producing a sheet-like material according to any one of claims 4 to 9, wherein the aqueous resin dispersion contains a thermo-sensitive coagulant. 11. The process for producing a sheet-like material according to any one of claims 4 to 10, wherein the aqueous resin dispersion contains a crosslinking agent. The sheet-like water producing method according to any one of claims 4 to 11, wherein the polymeric elastomer is a water-dispersible polyurethane.

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