JPH0480141B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a urethane containing densely entangled ultrafine fibers and/or bundles thereof and a polyether with a molecular weight of 500 to 5000 as a soft segment that can easily form a bonding complex with an anionic dye. This invention relates to a method for producing a leather-like sheet material, which has a silver surface formed by a composite material mainly composed of a polymer, has a supple texture and touch, is excellent in durability, and has a clear color tone with deep luster. [Prior Art] Conventionally, leather-like sheet materials having a grain layer are
A porous sheet material obtained by impregnating and/or coating and coagulating an elastic polymer into a fiber aggregate such as a non-woven fabric or a knitted/woven fabric is used as a base, and thick porous sheets made of a resin such as a urethane polymer are formed on the base. A grain layer is formed by laminating and integrating a porous layer or a non-porous layer, or a non-porous layer and a porous layer. Such leather-like sheet materials have an uneven surface due to coagulation spots and the like, so in order to prevent this from becoming apparent and to obtain a smooth grained layer surface, a coating layer is applied. The coating was made thicker or a thick undercoat layer was applied in advance. In addition, resins such as urethane polymers used for forming such silver surface layers have poor affinity for dyes, so it is difficult to color them with dyes, and even if they are colored, sufficient fastness cannot be obtained, so pigments are added to the resins. A coloring method was used in which the ingredients were dispersed and mixed in advance. Therefore, such leather-like sheet materials have a uniform gloss and cannot provide a deep and clear color tone, especially since the microporous layer is colored with pigments. In order to improve these drawbacks, methods have been proposed, such as adding a dye-containing resin layer to the outermost layer or dyeing the grain layer with a urethane polymer that has a high affinity for dyes. Even in these methods, since the urethane polymer has a porous structure in the grain layer, a strong rubbery texture and touch due to the elastic properties of the urethane polymer cannot be avoided, and moreover, only coloring with a strong artificial feel can be obtained. I couldn't help it. In addition, to improve the texture and touch of the grain layer,
Other methods have been proposed, such as combining a planar array of fine fiber bundles with a porous layer, or producing fine fiber fluff on the surface of a substrate and integrating the fluff fibers with resin to form a silver surface layer. However, in such a method, if the fiber bundles are strongly rubbed or subjected to repeated shear stress, peeling may occur along the alignment plane of the fiber bundles,
The problem was that the surface became fluffy. [Problems to be solved by the invention] As described above, conventional leather-like sheet materials have a supple feel, a deep luster, and a clear color tone, giving a luxurious feel that feels natural rather than artificial. Certain leather-like sheets could not be obtained. The present inventors have fully considered the problems of the conventional manufacturing technology for leather-like sheets, and have created a product that does not have the above-mentioned problems, has a clear surface color tone, and has a natural-looking appearance without being artificial. It has a deep luster, a very supple texture and touch, and is resistant to rubbing.
The present invention was finally arrived at after intensive study to find a method for producing a leather-like sheet material with excellent durability such as shear fatigue resistance. [Means for Solving the Problems] That is, the method for producing a leather-like sheet product of the present invention is a method for producing a leather-like sheet product having a grain layer, which is characterized by combining at least the following steps. It is. It is a multicomponent fiber made of at least two types of polymeric substances, and can have a structure in which an ultrafine fiber bundle and fibers from which ultrafine fibers can be branched are three-dimensionally intertwined by mechanical manipulation or chemical treatment. The step of obtaining a fibrous sheet is to blow a high-speed fluid stream onto at least one surface, which should be the silver surface, to form fibers with a dense entanglement density where some of the fiber bundles are branched and the distance between fiber entanglement points is 200 microns or less. a step of causing entanglement; a step of applying a urethane polymer containing a polyether with a molecular weight of 500 to 5,000 as a soft segment, which can easily form a bonding complex with an anionic dye, to the surface onto which the high-speed fluid stream has been sprayed; , a step of forming multi-component fibers into ultrafine fiber bundles, a step of coloring the urethane polymer with at least one dye selected from complex salt dyes, acid dyes, and reactive dyes; The method for producing a sheet product is such that the grain layer is a composite consisting of ultrafine fibers and/or bundles thereof and a resin, and the ultrafine fibers and/or bundles thereof are densely intertwined with each other. Moreover, the resin is based on the use of a urethane polymer containing polyether as a soft segment that can easily form a bonding complex with an anionic dye, and a composite made of this combination is used in the grain layer. For the first time, we are able to provide a leather-like sheet material that has a natural appearance with no artificial appearance on the silver surface, a deep and clear color tone with luster, and is supple in texture and touch and has excellent durability. It became possible to do so. [Function] Hereinafter, the method for producing a leather-like sheet product of the present invention will be explained in more detail. As the ultrafine fibers used in the present invention, it is preferable to use ultrafine fiber-forming fibers described below, which are modified into ultrafine fibers at an appropriate time during the processing process.
That is, the microfiber-forming fibers that can be used in the present invention include, for example, fibers with a chrysanthemum-shaped cross section in which one component is radially interposed between other components, multilayer bimetal fibers, multilayer bimetal fibers with a donut-shaped cross section, A sea-island type mixed spun fiber made by melt-mixing and spinning more than one component, and a high-quality fiber made of a large number of ultra-fine fibers that are continuous in the fiber axis direction and assembled and bonded and/or partially bonded with other components to form a single fiber. These fibers are molecular mutual array fibers, and two or more of these fibers may be used as a mixture or in combination. especially,
Multi-component ultrafine fiber-forming fibers that, when at least one component is dissolved and removed, yield a bundle of fibers consisting mainly of ultrafine fibers of 0.2 denier or less, preferably 0.05 denier or less, have a particularly supple texture and smooth surface. It is particularly preferably used because a leather-like sheet material having the following properties can be obtained. Further, the ultrafine fiber in the present invention is made of a polymeric substance having fiber-forming ability, such as polyamide such as nylon 6, nylon 66, nylon 12, copolymerized nylon, polyethylene terephthalate, copolymerized polyethylene terephthalate, polybutylene terephthalate, copolymerized nylon, etc. Examples include polyesters such as polymerized polybutylene terephthalate, polyolefins such as polyethylene and polypropylene, polyurethanes, polyacrylonitrile, and vinyl polymers. Also,
Examples of the binding component or the dissolving and removing component of the microfiber-forming fiber include polystyrene, polyethylene, polypropylene, polyamide, polyurethane, copolymerized polyethylene terephthalate easily soluble in alkaline solutions, polyvinyl alcohol, copolymerized polyvinyl alcohol, and styrene. Acrylonitrile copolymers, copolymers of styrene and higher alcohol esters of acrylic acid and/or higher alcohol esters of methacrylic acid, and the like are used. Polystyrene, styrene-acrylonitrile copolymers, and copolymers of styrene and higher alcohol esters of acrylic acid and/or higher alcohol esters of methacrylic acid are preferably used in terms of ease of spinning and ease of dissolution and removal. Furthermore, a copolymer of styrene and a higher alcohol ester of acrylic acid and/or a higher alcohol ester of methacrylic acid is more preferably used, since a high stretching ratio can be obtained and a fiber with high strength can be obtained. Further, in order to make the ultrafine fibers easier to branch, it is preferable to use a mixture of 0.5 to 30% by weight of a polymer such as polyethylene glycol in the binding component or the dissolving and removing component. The fineness of such microfiber-forming fibers is not particularly limited, but is preferably 1 to 10 deniers from the viewpoint of stability during spinning and ease of sheet formation. The ultrafine fibers in the grain layer of the present invention have a fineness of
It is preferably 0.2 denier or less. If it is thicker than 0.2 denier, the stiffness of the fiber is too high, which not only impairs the flexibility of the grain layer and the form of wrinkles on the surface.
Cracks tend to occur when rubbed, and the surface becomes uneven, making it difficult to form a silver surface layer that is smooth and has a deep luster and clear color tone. By using ultrafine fibers of 0.2 denier or less, preferably 0.05 denier or less, the fibers can be tightly intertwined for the first time. A leather-like sheet material that is flexible, hard to crack, has a smooth touch, a deep luster, and a clear color tone can be obtained. In the method for producing a leather-like sheet product of the present invention,
The fiber structure in the grain layer requires that ultrafine fibers and/or bundles thereof are densely intertwined with each other. In other words, the fiber entanglement density is high. One method for measuring the entanglement density of fibers is to measure the distance between fiber entanglement points, which will be described later.In the present invention, the fibers in the grain layer have an entanglement density of 200 microns or less as measured by this method. It is better to use what you have. This value
Structures larger than 200 microns, e.g.
This value is generally around 500 microns, and there are fiber structures with little entanglement in which the fibers are entangled only by needle punching, or structures in which ultrafine fibers or bundles thereof are simply arranged in a plane, or ultrafine fibers or their bundles are simply arranged in a plane. If the bundles are densely grown on the surface of the base material and are laid down to create a surface, there is little or no intertwining of the fibers, so the surface becomes fluffy when subjected to abrasion, kneading, repeated shearing force, etc. This tends to be undesirable as it tends to cause cracks to occur. In order to eliminate these drawbacks, it is desirable that the distance between fiber entanglement points be 200 microns or less, and more favorable results can be obtained if it is 100 microns or less. Here, the distance between fiber entanglement points is a value obtained by the following method, and is a measure of the denseness of fiber entanglement, and the smaller the value, the more dense the entanglement. be. That is, the attached drawing is a diagram for explaining how to determine the distance between fiber entanglement points in the present invention, and is an enlarged schematic diagram of the constituent fibers in the grain layer when observed from the surface side. The constituent fibers are f ₁ , f ₂ , f ₃ , ...,
Let the point where any two of these fibers f ₁ and f ₂ intertwine be a ₁ , and trace it to the point where the fiber f ₂ , which is on top of a ₁ , intersects with the other fiber below. Let the point where the two intersect be a ₂ (intersection point of f ₂ and f ₃ ). similarly
Let a ₃ , a ₄ , a ₅ .... Next, the linear horizontal distances a ₁ , a ₂ , a ₂ , a ₃ , a ₃ ,
a ₄ , a ₄ , a ₅ , a ₅ , a ₆ , a ₆ , a ₇ , a ₇ , a ₃ , a ₃ , a ₈ ,
a ₈ , a ₇ , a ₇ , a ₉ , a ₉ , a _{6 .} . . are measured, the average value of these many measured values is determined, and this is used as the distance between fiber entanglement points. In the method for producing a leather-like sheet of the present invention, the structure of the lower layer of the grain layer is not particularly limited, and may be a single structure of nonwoven fabrics, a laminated structure of nonwoven fabrics, or a layered structure of nonwoven fabrics. A knitted or woven fabric may be inserted inside to form an inseparable and integrated structure. By the way, the lower layer of the grain layer is mainly composed of ultrafine fiber bundles, and the grain layer's ultrafine fibers and/or
Or, the bundle is a branched ultrafine fiber bundle in the lower layer and intertwined more densely, and the fibers are substantially continuous in the grain layer and the lower layer, and the boundary between the two layers is a branched one. A fiber structure in which the degree of the fiber structure changes continuously is preferable because a sheet product with a unified feel can be obtained and the grain layer and the lower layer will not peel off. In addition, in the lower layer of the grain layer, ultrafine fiber bundles and ultrafine fibers branched from the bundles are entangled with each other, and the fibers are substantially continuous between the grain layer and the lower layer, and the entanglement density increases in the thickness direction. Those with simply different fiber structures are more preferable because a sheet product with a unified feel and high strength can be obtained. In addition, conventional leather-like sheets that use non-woven fabric as a base material are easily stretched by external forces and deformed plastically, making it difficult to return to the original shape. Therefore, resin was applied to the base material. However, the leather-like sheet material of the present invention, which has a fiber structure in which ultrafine fibers and/or bundles thereof are densely intertwined in at least the grain layer, has less abnormal stretching even if no resin is added to the lower layer. Good shape retention of objects. Of course, a resin such as a urethane polymer may be applied to the lower layer, and in this case, if a urethane polymer having the same composition as that used for the silver layer but made softer is mainly used, It is preferable because it does not cause uneven dyeing after dyeing due to the dye resistance of the urethane polymer, has a vivid hue, and has excellent fastness. Note that, depending on the purpose, a commonly used resin may of course be used as the binder. The amount of resin applied varies depending on the intended use of the sheet material, and when used for clothing, the amount of resin applied is preferably 0 to 80 parts based on the weight of the fiber. The resin used for the silver surface layer of the present invention has a molecular weight that allows it to easily form a bonding complex with an anionic dye.
Urethane polymers containing 500 to 5000 polyethers as soft segments are required. In particular, it is preferable that the polyether is contained in an amount of at least 5% in the total soft segment.
If it is less than 5%, it is difficult to obtain the desired deep and clear color tone. Polyethers used for the soft segment include polyoxymethylene glycol, polyoxybutylene glycol, polyoxytetramethylene glycol, etc. Among them, polyoxymethylene glycol takes a meandering structure in an aqueous solution and easily forms an anion. Urethane polymers made from these polymers are particularly preferred because they can form binding complexes with dyes and have good affinity with dye molecules such as complex dyes, acid dyes and reactive dyes. The term "bond complex" as used herein refers to a bond complex formed by an oxygen atom site in a polyether having a lone pair of electrons acting as a Lewis base and bonding to an anionic dye through a hydrogen bond. The molecular weight of the polyether in the present invention needs to be 500 to 5000 in order to bring the thermal softening point, bending resistance, solvent resistance, etc. of the urethane polymer into a practical range. In order to further improve mechanical properties, soft segments composed of polyesters such as polyethylene adipate, polybutylene adipate, polypropylene adipate, polyhexamethylene adipate, and polycaprolactone, as well as copolymer type polyesters of these, are used to improve colorability and mechanical properties. They may be blended or copolymerized in appropriate amounts in view of the balance between the two. Further, the urethane polymer used in the present invention is not limited to a substantially linear type polyurethane, but also a cross-linked type polyurethane, which is cross-linked using a cross-linking agent such as a trimer of hexamethylene diisocyanate, if necessary. It may be. Generally, when a cross-linked type polyurethane is used for the grain layer, it has good scratch resistance, but has the disadvantage of poor bending fatigue resistance. Since it is formed as a composite with coalescence, it is preferable because it has excellent bending fatigue resistance and is also effective in improving hot water resistance. As a method for producing such polyurethane,
A prepolymer method in which a prepolymer having an isocyanate group at the end obtained from a commonly used organic diisocyanate and a polymer diol is chain-extended using a chain extender, or an organic diisocyanate, a polymer diol, and a chain extender are reacted simultaneously. Any method such as the one-shot method can be applied. As the polymeric diol for soft segments used in the present invention, polyether diols such as the aforementioned polyoxyethylene glycol, polyoxypropylene glycol, and polyoxytetramethylene glycol may be used alone or in combination, or the polyether diol and polyethylene glycol may be used alone or in combination. Adipate, polybutylene adipate, polypropylene adipate, polyhexamethylene adipate, polyester such as polycaprolactone, or a copolymer type polyester diol of these are blended so that the polyether diol component is contained at 5% or more, or polyether - May be used as an ester copolymer. Examples of organic diisocyanates include aromatic diisocyanates such as phenylene diisocyanate, tolylene diisocyanate, and diphenylmethane-4,4'-diisocyanate, araliphatic diisocyanates such as xylylene diisocyanate, ethylene diisocyanate, triethylene diisocyanate, tetramethylene diisocyanate, and hexamethylene. Aliphatic diisocyanates such as diisocyanate, hydrogenated tolylene diisocyanate,
There are alicyclic diisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane-4,4'-diisocyanate, but among these, aromatic diisocyanates with good mechanical properties such as heat resistance, solution stability, and tensile strength are preferred for practical purposes. -4,4'-diisocyanate is preferably used. Further, alicyclic diisocyanate such as isophorone diisocyanate is preferable since a non-yellowing type polyurethane can be obtained. As a chain extender, water, ethylene glycol,
Low molecular weight diols such as propylene glycol and 1,4-butanediol, aliphatic diamines such as ethylene diamine and propylene diamine, 4,4'-
Aromatic diamines such as diaminodiphenylmethane and tolylene diamine, piperazine, 1,2 or 1,4-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, alicyclic diamines such as isophorone diamine, ethanolamine, diethanolamine, Alkanolamines such as aminoethylethanolamine, hydrazines,
There are dihydrazides such as succinic acid dihydrazide and adipic acid dihydrazide, but diamine compounds are preferred from the viewpoint of heat resistance, and 4,4'-diaminodiphenylmethane is particularly preferred from a practical standpoint.
Further, 4,4'-diaminodicyclohexylmethane is more preferred in terms of light resistance. Of course, these may be used alone or in combination. The above production is usually carried out in a solvent, and suitable solvents include dimethylformamide, dimethylacetamide, dimethylsulfoxide, methyl ethyl ketone, dioxane, tetrahydrofuran, ethyl acetate, and triene, among which dimethylformamide (hereinafter referred to as DMF) is used. is preferably used. In addition, the urethane polymer obtained by the above method may include polyamide, polyester, polyvinyl chloride,
Polyacrylic ester copolymer, neoprene,
Synthetic resins such as styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, polyamino acids, polyamino acid polyurethane copolymers, silicone resins, natural polymer resins, or mixtures thereof may be mixed, or if necessary, these may be mixed. The material may be applied to the surface of the grain layer of the present invention at a generally thin thickness such as 10 microns or less. Furthermore, if necessary, plasticizers, fillers, stabilizers, crosslinking agents, etc. may be added. Furthermore, urethane polymers that contain not only urethane polymers but also other resins and additives have a particularly flexible texture and feel.
It is preferably used because a durable grain layer can be obtained. Further, a crosslinked urethane polymer may be applied to the surface of the grain layer of the present invention in a thickness of 0.2 to 10 microns, preferably 0.2 to 3 microns. The adhesion structure of the resin mainly composed of urethane polymer in the grain layer is not particularly limited and may vary depending on the purpose, but if flexibility and soft feel are particularly required, such as for clothing, the grain layer Those with a structure in which more of the resin is attached as it gets closer to the surface, and the extremely thin layer on the outermost surface of the grain layer have a particularly large amount of resin attached, and in other cases, there is no resin attached at all or only a small amount of resin is attached. It is preferable to have a structure in which the amount of Further, when particularly high scratch resistance is required, a structure in which the voids in the grain layer are filled with resin almost without any gaps is preferable. One of the intended objects of the present invention is a leather-like sheet material that has a smooth texture and touch, has a deep luster, and exhibits a clear color tone, which is used for the grain layer as described above. This cannot be achieved by simply coating a urethane polymer on a conventional porous sheet. This can only be achieved by combining a densely intertwined fiber tangled body and applying the coloring method described below. The luster of the present invention has a deep and clear color tone,
The urethane polymer applied to the leather-like sheet material, especially the grain layer, is an anionic dye selected from complex dyes, acid dyes, and reactive dyes that have a negative charge in an aqueous solution. The ultrafine fibers of 0.2 denier or less constituting the leather-like sheet material are colored with the above dyes, and if the ultrafine fibers are made of a polyamide polymer, the ultrafine fibers are colored with the above dyes. In the case of materials other than molecular polymers, they can be obtained by dyeing the polymer with a dye most suitable for the polymer. If the microfibers are made of poamide-based polymers, they will have a high affinity with the dyes mentioned above, and can be colored at the same time as the urethane polymers. In particular, reactive dyes are needed to obtain high fastness in light to medium colors. Preferably, a 1:2 type complex salt dye, which has a high hiding power and can be dyed in a neutral bath, is preferably used for medium to dark colors. On the other hand, when the ultrafine fibers are other than polyamide-based polymers, the urethane polymer may be colored with the dye before or after the ultrafine fibers are colored. ,
This does not impede the effects of the present invention. Further, the coloring of the urethane polymer may be performed after or before the urethane polymer is applied to the sheet-like material made of the ultrafine fibers. In addition, dyes and/or
Alternatively, a suitable amount of pigment can be added in advance to promote coloring properties. A more specific explanation of the method for producing a leather-like sheet material of the present invention, which consists of a combination of the above-mentioned steps, is as follows, for example. First, ultrafine fiber-forming fibers were produced, for example, in
- Manufactured using the spinning device shown in Publication No. 18369, stapled, passed through a card and a cross wrapper to form a web, and then needle punched to entangle the ultrafine fiber-forming fibers to form a fiber sheet. do. Alternatively, following the spinning of the microfiber-forming fibers, they are stretched and placed randomly on a wire mesh, and the obtained web is needle punched in the same manner as described above to form a fiber sheet. Alternatively, a fiber sheet may be formed by placing the microfiber-forming fibers on a nonwoven fabric, woven fabric, or knitted fabric made of ordinary fibers or other microfiber-forming fibers and entwining them inseparably. Next, the fiber sheet thus obtained is brought into contact with a high-speed fluid stream to cause the portion corresponding to the grain layer to branch into ultrafine fibers and/or bundles thereof, and at the same time to intertwine them densely. The fluid here refers to liquid or gas, and in special cases it may contain extremely fine solids, but water is the most suitable from the viewpoint of ease of handling, cost, and amount of collision energy as a fluid. Preferably used. Furthermore, depending on the purpose, various organic solvents capable of dissolving some components of the ultrafine fiber-forming fibers, or aqueous solutions of alkalis or acids such as sodium hydroxide can also be used. These fluids are pressurized and injected from small-diameter nozzles or narrowly spaced slits into a high-speed columnar or curtain-like flow, which is brought into contact with the fiber sheet to branch and entangle the fibers. The pressure applied to the liquid varies depending on the ease with which the ultrafine fiber-forming fibers or ultrafine fiber bundles branch. For fibers that are easy to branch, a relatively low pressure of 5 to 100 kg/cm ² may be sufficient, but for fibers that are difficult to branch. For fibers, high pressures of 100-300 Kg/ ^cm2 are preferred. It is also possible to increase the degree of branching and entanglement by increasing the number of contacts, and the pressure may be changed each time the contacts are made. After that, if it is necessary to make the ultrafine fiber-forming fibers ultrafine, the ultrafine fiber-forming fibers may be peeled off by applying a physical action, or they may be treated with a solvent that dissolves at least a portion of the components. The resulting fiber sheet is treated to dissolve and remove some of the components. Further, if necessary, it is impregnated with a solution or dispersion of a binder resin such as a polyurethane elastomer and coagulated by a wet or dry method. Here, the part of the component may be dissolved and removed before the treatment with the high-speed fluid flow, and in this case, by dissolving and removing the part of the component, the ultrafine fiber-forming fiber of the fiber sheet becomes the ultrafine fiber. This is a preferred method because it is metamorphosed into bundles and can be easily branched and entangled at high speed with low fluid pressure. Further, high-speed fluid flow treatment may be performed before and after the step of dissolving and removing the partial components. In addition to the above, the step of applying the binder resin can also be carried out between the high-speed fluid flow treatment step and the step of dissolving and removing some components of the fibers. It is necessary that the applied resin does not dissolve with the solvent used to dissolve and remove the components, but a space where some of the components existed may be created between the ultrafine fiber bundles of the obtained resin sheet and the resin. This is a preferred method for making the texture more flexible as it increases the degree of freedom of movement. On the other hand, performing high-speed fluid flow treatment after applying a binder resin is not a desirable method because when a large amount of resin is applied, the fibers are bound by the resin, so branching and entanglement hardly occur. . Thereafter, the solution or dispersion of the resin for the grain surface layer of the present invention described above is applied to the layer in which the ultrafine fibers and/or bundles thereof of the obtained fiber sheet are intertwined by reverse roll coating, gravure coating,
Apply by knife coating, slit coating, spraying, etc., solidify by wet or dry method, overlap and pressurize on the roll surface or sheet surface, and heat as necessary to integrate the fiber and resin. At the same time, the surface is smoothed to form a silver surface. Here, it is also a preferable method to subject the fiber sheet to a treatment such as pressing to smooth the surface before applying the resin. When forming the silver surface, it is preferable to use an embossing roll or a textured sheet with a textured surface because integration, smoothing, and texture can be performed at the same time. Further, the partial component dissolution and removal of the ultrafine fiber-forming fiber can also be carried out after the formation of such a grain layer, and in this case it is particularly preferable because a softer texture can be obtained. One of the major features of the present invention is that such a method can be used. Furthermore, it may be subjected to dyeing by the method described above, and may be subjected to treatments such as applying a finishing agent and rolling, if necessary. [Effects of the Invention] The leather-like sheet material obtained by the method of the present invention has a supple texture, a smooth touch, a deep luster, a clear color tone, and an appearance that looks natural without being artificial. It also has good durability such as bending resistance, shear fatigue resistance, and scratch resistance, so it can be used for various products such as silver-finished artificial leather for clothing, shoe uppers, belts, bags, gloves, and ball leather. It is preferably used for this purpose. [Examples] The following examples are provided to clarify the present invention, and the present invention is not limited thereto. In each example, parts and percentages are by weight unless otherwise specified. Moreover, the value of the average intercrossing point distance was taken as the average value of 100 measured values. Example 1, Comparative Example 1 Copolymer of acrylic acid and styrene (hereinafter referred to as AS
One filament has 12 island components in a ratio of 60 parts of resin) as a binding component and 40 parts of nylon 6 as an ultra-fine fiber component, and a large number of ultra-fine fiber components are included in the island components. A 3.5 denier, 51 mm staple of polymer interlayer fibers as shown in Japanese Patent Publication No. 47-37648 is used to form a web through a card cross wrapper, and then a needle with a hook count of 1 is formed. A nonwoven fabric (A) was produced by needle punching the fibers of the mutually arranged polymer. The purpose of the nonwoven fabric (A) was 380 g/m ² and the apparent density was 0.19 g/cm ³ . Water with a pressure of 100 kg/cm ² is applied from nozzles in which holes with a diameter of 0.1 mm are arranged in a row with a distance between the centers of the holes of 0.6 mm, while moving the nonwoven fabric (A) while vibrating the nozzles. A nonwoven fabric (B) was produced by spraying contact with the surface at high speed and treating both sides 10 times under the same conditions. The obtained nonwoven fabric (B) had a fiber structure in which the surface layer polymeric mutually arranged fibers were branched into ultrafine fibers or bundles thereof, and were densely intertwined with each other. Next, the nonwoven fabric (B) was shrunk in hot water at 85°C. On the other hand, the nonwoven fabric (A) was immersed in a 15% aqueous solution of polyvinyl alcohol (hereinafter referred to as PVA) heated to 85°C.
After shrinking and drying the nonwoven fabric at the same time as the PVA impregnation, the nonwoven fabric (A) is impregnated with a 10% DMF solution of polyester-based polyurethane, and the liquid adhering to the surface is directly poured into a 30% DMF aqueous solution without removing it. It was introduced and coagulated, and then thoroughly washed in hot water at 80°C to remove PVA and DMF. Next, the nonwoven fabric (A) and the nonwoven fabric (B) were passed through a heating roll to smoothen their surfaces. Thereafter, polyoxyethylene glycol (hereinafter referred to as PEG) having a molecular weight of approximately 2000 and a hydroxyl group at the end, 4,4'-diphenylmethane diisocyanate (hereinafter referred to as MDI) and 4,4'-
Diaminodiphenylmethane (hereinafter referred to as MBA)
A 10% solution of a urethane polymer obtained by reacting with a molar ratio of 1:2:1 using a prepolymer method.
It was applied using a gravure roll so that the amount was 4 g/m ² (in terms of urethane polymer). Thereafter, the applied surface was pressed through a heated embossing roll to emboss a leather-like grain pattern. Then, the AS
The resin was almost completely extracted and removed, followed by drying to evaporate and remove residual trichlorethylene. These sheets (A) and (B) are dyed with 1:2 type metal-containing complex salt dye.
Bath ratio 1:50 using Irgalan Black GBL200%,
Dye concentration 1.0g/liquid temperature 95℃ using jet dyeing machine
It was dyed for 60 minutes and finished in the usual way. The leather-like sheet material obtained from the nonwoven fabric (B) has a natural appearance with a vivid grain pattern, a soft and supple texture, and a luxurious feel with a deep and clear color tone. It became a leather-like sheet material. On the other hand, in the leather-like sheet material obtained from the nonwoven fabric (A) of Comparative Example 1, in addition to the grain pattern, streaks of unnatural color tone and unevenness were observed along the ultrafine fiber bundles in a state where blood vessels stood out. In addition, cracks that occurred during dyeing were seen here and there along the ultra-fine fiber bundle, exposing the ultra-fine fibers. In addition, the touch was stiff and hard compared to the product of the present invention, and the color tone was muddy and artificial. The urethane polymer and finishing agent applied to these leather-like sheets were extracted and removed with a solvent, and the distance between fiber entanglement points of the constituent fibers on the surface of the grain layer was measured. The average distance between fiber entanglement points was 378 microns for the nonwoven fabric (A), and 56 microns for the nonwoven fabric (B). Furthermore, when these leather-like sheet materials were pinched with fingers, bent at an acute angle, and rubbed forcefully against the thighs of pants, no change was observed in the appearance of the leather-like sheet materials of the present invention using the nonwoven fabric (B). However, in the case of the nonwoven fabric (A), the silver layer had peeled off and the fuzz was exposed. Examples 2 to 6, Comparative Example 2 The nonwoven fabric (B) produced in Example 1 was heated to 85°C.
The nonwoven fabric was immersed in an 8% aqueous solution of PVA, and simultaneously impregnated with PVA, the nonwoven fabric was shrunk, and the moisture was removed by drying.The fabric was then dipped in trichlorethylene, and the AS resin was extracted and removed by repeating dipping and squeezing, followed by drying. Next, the same urethane polymer as in Comparative Example 1 was impregnated with a 7% DMF solution to which a small amount of carbon black had been added, and then introduced into water and solidified. Thereafter, it was thoroughly washed in hot water at 80°C, and PVA and DMF were removed. Next, PEG with a molecular weight of approximately 2000 and PEG with a molecular weight of approximately
The mixing ratio of 2000 with polyethylene butylene adipate is (C) 100/0 (Example 2) (D) 50/50 (Example 3) (E) 10/90 (Example 4) (F) 5/95 (Example 5) (G) 3/97 (Example 6) (H) 0/100 (Comparative Example 2) A polymeric diol, MDI, and MBA were reacted in a molar ratio of 1:2:1. A 10% DMF solution of the obtained urethane polymer was gravure coated at a rate of 6 g/m ² (in terms of urethane polymer), and after drying, it was pressed through a heated embossing roll to be integrated to form a composite. At the same time, a leather-like grain pattern was embossed. Furthermore, the opposite side was buffed to make the hair stand up. These sheet materials (C), (D), (E), (F), (G), (H) are
Vinyl sulfone type reactive dye: Dlamira Brill Red
Using F3B, dyeing was carried out using a jet dyeing machine at a bath ratio of 1:50 and a dye concentration of 2.0 g for 60 minutes at a liquid temperature of 50°C, followed by finishing treatment using a conventional method. These leather-like sheets obtained have a texture with low repulsion and a sense of unity, with one side having fluff of relatively long ultra-fine fibers, and the other side having an elegant appearance. Leather-like sheets of (C), (D), (E), and (F) that have a silver surface and have a structure extremely similar to natural silver-plated leather, and as shown in Table 1. The material had a silver surface with a clear color tone with deep luster, but the leather-like sheet material (G) had improved coloring properties, but there were some speckled patterns resulting from uneven dyeing. Was. Compared to these, the leather-like sheet material (H) showed almost no coloring in the resin portion of the grain surface, so the coloring of the grain layer was extremely uneven and had poor commercial value. The color fastness of (C), (D), (E), (F), and (G) was at a level with no problems as shown in Table 1.

【table】

【table】 [Brief explanation of drawings]

The figure is an enlarged schematic diagram of the constituent fibers in the grain layer when observed from the surface side, and is a diagram for explaining how to determine the distance between fiber entanglement points employed in the present invention. In the figure, f ₁ , f ₂ , f ₃ , f ₄ , f ₅ and f ₆ indicate constituent fibers, and a ₁ , a ₂ , a ₃ , a 4 , a ₅ , a ₆ , a ₇ , a _{8 and} a ₉ shows the intertwining points of the constituent fibers.

Claims (1)

[Scope of Claims] 1. A method for producing a leather-like sheet product having a grain layer, characterized by combining at least the following steps. It is a multicomponent fiber made of at least two types of polymeric substances, and can have a structure in which an ultrafine fiber bundle and fibers from which ultrafine fibers can be branched are three-dimensionally intertwined by mechanical manipulation or chemical treatment. The step of obtaining a fibrous sheet is to blow a high-speed fluid stream onto at least one surface, which should be the silver surface, to form fibers with a dense entanglement density where some of the fiber bundles are branched and the distance between fiber entanglement points is 200 microns or less. a step of causing entanglement; a step of applying a urethane polymer containing a polyether with a molecular weight of 500 to 5,000 as a soft segment, which can easily form a bonding complex with an anionic dye, to the surface onto which the high-speed fluid stream has been sprayed; , a step of forming multi-component fibers into ultrafine fiber bundles, a step of coloring the urethane polymer with at least one dye selected from complex dyes, acid dyes, and reactive dyes.