JP2002266251A - Leather-like sheet substrate and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a leather-like sheet substrate which has an excellent hand and comprises a polymer elastomer and joint type conjugated fibers not peeled or split in the longitudinal direction of the fibers even after a carding treatment and a needle punching treatment and can be split in the subsequent treatment in a hot water bath. SOLUTION: This method for producing the leather-like sheet substrate is characterized by subjecting a nonwoven fabric comprising joint type conjugated staple fibers to a splitting treatment in a hot water bath before and after a polymer elastomer is imparted to the nonwoven fabric. The joint type conjugated staple fibers are produced by disposing a polymer A and a polymer B in a five or more layer-laminated structure in the cross section of each fiber and covering the polymer B with the polymer A so that the ratio of the maximum diameter of the fiber to the thickness of the cover is limited within a specific range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a leather-like sheet substrate and the obtained leather-like sheet substrate.
More specifically, the present invention enables ultrafine fibers to be formed without using an organic solvent or an alkaline aqueous solution, and substantially separates and splits in the longitudinal direction of the fibers even after card processing and needle punch processing. The present invention relates to a method for producing a leather-like sheet base comprising a fiber obtained by dividing a joint type composite staple into ultrafine fibers and a polymer elastic body, and a leather-like sheet base obtained.

In the production of ultrafine fibers having a single fiber of 0.1 decitex or less, direct spinning tends to cause yarn breakage, so there is a limit in fineness, and a composite spinning method has been conventionally used. Composite spun fibers obtained by the composite spinning method are roughly classified according to the state of the cross section of the fiber. When the two components are divided into a high degree, they are joined together (multilayer bonding type, petal type, etc.), and one component has a high degree in other components. There is a sea-island type that is dispersed. In the case of the sea-island type fiber, ultrafine fibers of 0.001 denier or less can be obtained by removing the sea component. However, in order to remove the sea component, for example, when the sea component is polyethylene or polystyrene, etc. Requires the use of organic solvents such as toluene and perchrene,
In the case of modified polyethylene terephthalate which is easily soluble in alkali, it is necessary to use a high-concentration alkali solution.
In recent years, use of such an organic solvent and reduction of a high-concentration alkaline liquid and a neutralized waste liquid have been demanded from an environmental point of view.

Further, since the removed sea component is difficult to reuse, an increase in the amount of waste is inevitable. From the viewpoint of ecology, it is preferable to obtain an ultrafine fiber from a bonded fiber which does not require removal of one component. . In such a joint type conjugate fiber, a fiber having a sharp edge or an ultrafine fiber is formed by the separation of the components, and a method of separating or dividing the conjugate fiber is disclosed in JP-A-54-96181. A method in which one component is swollen with a liquid containing a chemical such as benzyl alcohol and separated from each other by the force, JP-B-53-10170 and JP-A-2-169.
No. 722, Japanese Unexamined Patent Publication No. 9-217233, and physical force, that is, rubbing, crushing, buffing or the like, treating the surface, or jetting a water jet stream. Forcible separation, and a method of dissolving a small amount in a low-concentration alkaline solution to separate them from each other.

[0004]

In the case of producing a leather-like sheet from such fibers, the splitting treatment is carried out after producing a nonwoven fabric or after producing a nonwoven fabric and applying a polymer elastic body. Although it is possible to obtain a leather-like sheet having a soft and excellent texture, if splitting occurs in the process of forming a nonwoven fabric before that, process passability and yield will be significantly deteriorated,
The resulting non-woven fabric is also non-uniform and has a very poor feel. Specifically, when a card is used when manufacturing a nonwoven fabric, the components of the bonded conjugate fiber are separated, the fiber is thinned, and a nep is generated. It becomes necessary to accumulate in the card device, and stable spinning cannot be performed. In addition, when a needle punch is used to entangle the fibers, there is a problem that peeling occurs due to damage, the single fibers are hardly entangled, and the peel strength of the nonwoven fabric does not increase.

However, on the other hand, there is a method of increasing the adhesiveness of the two components constituting the fiber in order not to cause such deterioration in the processability, but this method causes a problem in forming a nonwoven fabric. However, even if the above splitting process is performed later as a post-process, splitting is not performed at all, only a small portion is split, or very strong physical force is required to split all. It is not a preferable method because it requires a long-time treatment or requires the use of a high-concentration alkaline solution.

Therefore, as another method, a method has recently been proposed in which one of the two components is coated with the other component. As such an example, JP-A-2000-2000
Japanese Patent Publication No. 129538 describes a composite fiber having a petal-shaped cross-sectional structure in which one component covers the other component by eight or more petals. It is difficult to completely split the number of layers as much as the apparent number of layers because the interval becomes narrower and one component is substantially connected at the center, and a leather-like sheet made of a nonwoven fabric obtained from such fibers Is inferior to a leather-like sheet obtained from a conventional nonwoven fabric made of ultrafine fibers.

Further, as described above, as a splitting method of two components, a method of swelling one component with a liquid containing a chemical solution such as benzyl alcohol and separating the components from each other by the force,
Physical force, i.e., scraping, rubbing, treating the surface with buffing, etc., jetting a water jet flow, etc., forcibly separating, low concentration alkaline solution, dissolve a little Although the method of separating from each other has been mentioned, in the method of, since an organic solvent is used as a swelling agent, it becomes a problem in terms of ecology,
In the method of (1), when producing a leather-like sheet substrate having a thickness of about 1.0 to 2.0 mm used for sports shoes and the like, the separation or division of the fiber component progresses particularly toward the center. In the method of inferior in terms of texture because it does not, compared to the extraction treatment using a high concentration alkaline solution, although overwhelmingly small,
At present, each has its own problems, such as the problem of handling and disposal of hazardous materials due to the use of alkaline liquids.

[0008]

Means for Solving the Problems The present inventors have found that even after card treatment and needle punching treatment, the fiber can be formed into a nonwoven fabric without substantially peeling and splitting in the longitudinal direction of the fiber. In the fiber treatment, the use of bonded composite staple fibers, which can be split quickly with the physical force of substantially the same level as used in conventional relaxation processing, without the use of organic solvents or alkaline aqueous solutions, contributes to environmental protection. The object of the present invention is to obtain a leather-like sheet made of ultrafine fibers having a small load on the surface and having an excellent texture, and as a result of intensive studies, it has been found that the above-mentioned problem can be solved by using the method described below.

That is, the present invention provides a method for producing a leather-like sheet substrate, comprising the following steps (1) to (3): (1) → (2) → (3) or (1) → (3) → (2)
A method for producing a leather-like sheet substrate, characterized in that the method is performed in the following order. (1) In a fiber composed of two types of polymer components having different A and B, the total number of laminated layers of component A and component B is 5 or more, and component A has a cross-sectional structure in which component B is coated. And, the ratio (t / d) of the minimum thickness (t) of the component A of the covering portion to the maximum fiber diameter (d) was in the range of 0.005 to 0.03, and the composite staple fiber was constituted. A step of manufacturing a nonwoven fabric, (2) a step of providing a polymer elastic body to the nonwoven fabric, and (3) a component A and a component B at 100 to 160 ° C.
The present invention is a method for producing a leather-like sheet, in which the following step (3 ′) is performed in place of the step (3) of the above-mentioned production method. (3 ′) a step of splitting the fiber component A and the component B during the dyeing treatment at 100 ° C. to 160 ° C. using the disperse dye or during the reduction treatment performed after the dyeing treatment;

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The bonded conjugate fiber used in the present invention has a multi-layer laminated cross section in which component A of component A and component B of component B cover component B. Ratio (t / d) between the minimum thickness (t) of the component A having the structure and the coating layer portion and the maximum diameter (d) of the fiber
Is within the range of 0.005 to 0.03. Further, the preferable range of t / d is 0.007 to
It is in the range of 0.02. When t / d is less than 0.005, the coating of the polymer B is insufficient, and any one of the steps of fiber drawing, mechanical crimping, card opening, and needle punch entanglement is performed. Since a large amount of cracks are generated, for example, a large amount of neps are generated in the card device, which causes a problem that stable web production becomes impossible. On the other hand, when t / d is larger than 0.03, the fiber can be stably produced without cracking until the nonwoven fabric manufacturing step, but the fiber is easily split in a hot water bath or the like in the subsequent splitting processing step. You will not be able to do it. For example, when the polymer A is a polyester compound and the t / d is greater than 0.03, the fibers cannot be split easily in a hot water bath in order to make the fibers extremely fine. The result was that the treatment with a liquid had to be used, and the present invention was not satisfied.

The polymers A and B which can be used in the bonded conjugate fiber of the present invention can be used in accordance with the intended use and performance if they are combined in consideration of the relative balance between the SP value and the melt viscosity. It can be appropriately selected from spinnable polymers. Examples thereof include polyester polymers such as polyethylene terephthalate and polybutylene terephthalate, polyolefin polymers such as polyethylene and polypropylene, polyamide polymers such as nylon 6 and nylon 66, and other polystyrene polymers.
Examples thereof include a polyvinyl alcohol-based polymer and a vinyl alcohol-ethylene copolymer.
Species, or two or more species are used. Among them, since the leather-like sheet obtained is excellent in texture, the component A is preferably a polyester polymer, especially a polyethylene terephthalate polymer, and the component B is preferably a polyamide polymer.

The polyester polymer represented by the polyethylene terephthalate polymer described above may comprise one or more other dicarboxylic acid components, oxycarboxylic acid components, and other diol components, if necessary. It may have as. In this case, as other dicarboxylic acid components, aromatic dicarboxylic acids such as diphenyldicarboxylic acid and naphthalenedicarboxylic acid or ester-forming derivatives thereof; dimethyl 5-sodium sulfoisophthalate, bis (2-sodium sulfoisophthalate) (2 -Hydroxyethyl) such as a metal sulfonate group-containing aromatic carboxylic acid or a derivative thereof; oxalic acid, adipic acid,
Examples thereof include aliphatic dicarboxylic acids such as sebacic acid and dodecane diacid or ester-forming derivatives thereof.
Examples of the oxycarboxylic acid component include p-oxybenzoic acid, p-β-oxyethoxybenzoic acid, and ester-forming derivatives thereof.
Diethylene glycol, 1,3-
Aliphatic diols such as propanediol, 1,6-hexanediol, and neopentyl glycol; and 1,4-bis (β-oxyethoxy) benzene, polyethylene glycol, polybutylene glycol, and the like.

The polyamide polymers mentioned above are known nylon 4, nylon 6, nylon 66, nylon 7, nylon 610, nylon 11, nylon 12, and bis (p
(Aminocyclohexyl) amide and polyamide from 1,10-decamethylene dicarboxylic acid, and polyamide from 1,9-nonamethylene dicarboxylic acid. These polyamide components and other components do not impair the effects of the present invention. Examples thereof include those copolymerized within the range, and those obtained by mixing these polyamide components and other components within a range that does not impair the effects of the present invention. Among these polyamide compounds, nylon 6 can be preferably used because the leather-like sheet obtained has an excellent texture.

The weight ratio of the polymer component A to the component B in the fiber is not critical as long as the desired multilayered cross-sectional structure is formed, but is preferably 90/10 to 10 /.
90, more preferably 80/20 to 20
/ 80 range. However, when either one of the weight ratios of the A and B polymer components is less than 10%, when the components A and B are alternately arranged in the spinneret before discharging from the spinneret. Since the amount of the polymer is small, it tends to be difficult to form a target cross section.

In the present invention, the cross-sectional structure of the fiber is A,
It is important that it is a multi-layer laminated type having 5 or more layers in total. In the present invention, such fibers are not only capable of being split smoothly, but also have a flat cross-sectional surface portion and an original side surface portion of the fiber obtained by the splitting process, and are obtained by the splitting process. When the cross-sectional shape of the fiber to be applied stresses the leather-like sheet, the fiber is easily broken in the direction of the relatively flat splitting surface, for example, a circular cross-section formed with the same fineness, an elliptical cross-sectional structure. This has the effect that the texture becomes more flexible as compared to a leather-like sheet manufactured from a nonwoven fabric made of fibers having the same. When the number of layers is four or less, the fineness is not reduced even after the splitting treatment, and the texture of the obtained leather-like sheet is inferior. More preferred number of layers is 9 to 2
The range is 0 layers. Further, when the cross-sectional structure is a petal type, the interval between the two components becomes narrower toward the center portion, and furthermore, one component is substantially connected at the center portion.
It is difficult to split the fibers completely to the apparently counted layers, and the texture of the resulting leather-like sheet is inferior.

In the hollow petal type, splitting is possible, but due to the presence of the hollow portion, the external stress of the fiber is remarkably inferior to that of the multilayer laminating type. Cracks may occur. In addition, the petal type and the hollow petal type have a slower entanglement in the needle process than the multi-layered type, and the entanglement efficiency between the fibers is low, so the obtained leather-like sheet has a mechanical strength such as tensile strength, tear strength and peel strength. Poor physical properties.

In order to produce the bonded conjugate fiber having a multilayer cross-section in the present invention, a polymer component A and a component B are used.
Are made into a molten state, and the molten state is alternately arranged by a conventional method, guided to a die nozzle hole, and discharged from the nozzle hole. That is, both the components A and B are alternately arranged, and the component B and the metal of the base are brought into contact with the metal of the base by the surface tension of the component B until the polymer is discharged from the pores inside the base. Is rounded, and the component A flows into the clearance, whereby a bonded conjugate fiber having a coating in which the entire outer periphery of the cross section is covered by the component A can be obtained. The film thickness can be controlled by the SP value (solubility parameter) of the components A and B used and the absolute and relative values of the viscosity during spinning. For example, when the SP values of the polymer components A and B are high, the polar groups of both polymers tend to be rounded due to surface tension because the polar groups of the two polymers are located as far apart from each other as possible.

Further, when the SP value of the component B is higher than the SP value of the component A, the end of the polymer B is rounded, and the polymer A easily flows into the gap between the base and the entire periphery of the cross section of the fiber. It becomes easy to form a thick film. However, SP of component B
Even if the value is higher than the SP value of the component A, the apparent melt viscosity of the component A during spinning is higher than the apparent melt viscosity of the component B, and the effect of the melt viscosity difference is relatively higher than the SP value difference. In the case of superiority, the end of the polymer A is likely to be rounded, and it is difficult to form a film. Further, when the apparent melt viscosity of the component B at the time of spinning is higher than the apparent melt viscosity of the component A, the end becomes rounder, and the polymer A easily flows into the gap between the die and the entire periphery of the cross section of the fiber. It is easy to form a coating covering the surface. However, even if the apparent melt viscosity of component B is higher than the apparent melt viscosity of polymer A, the SP value of component A during spinning is higher than the SP value of component B,
If the difference is larger than the difference between the values, the end of the polymer A is likely to be rounded, and it is difficult to form a film.

In order to make the end of the polymer B round and to make it easier for the polymer A to flow into the gap between the end and the base, depending on the balance between the SP value or the melt viscosity of the component A and the component B, A After alternately arranging both polymers B and B in a molten state, it is necessary to lengthen the time until the polymer is discharged from the base nozzle hole. That is, by increasing the time from the die hole to the discharge, the polymer A wraps around due to the shearing effect due to the contact between the metal surface of the die nozzle hole and the polymer A, so that a film of the polymer A is easily formed. It is.

The single-fiber fineness of the bonded composite staple fiber is not particularly limited, and can be arbitrarily selected depending on the application. However, since the leather-like sheet obtained has an excellent texture, the fineness is 0.5 dtex to 10 dtex. And more preferably 2 to 7 dtex.
Also, the cut length can be arbitrarily selected depending on the use. The average fineness of each layer after splitting is 0.01
It is preferable from the viewpoint of the texture of the leather-like sheet that a range of from 1.0 to 1.0 dtex is obtained. Further, as a fiber cross-sectional shape of each layer after splitting, the length of each layer with respect to the width of each layer is 3 to 50 on average. It is preferable that it is in the range from the viewpoint of the flexibility of the obtained leather-like sheet. The cross-sectional shape of the bonded composite staple fiber is preferably such that the outer periphery is elliptical and the lamination surface is substantially parallel to the minor axis of the ellipse. Multilayer lamination, and the shape in which the component A is coated with the component B does not substantially separate or split in the longitudinal direction of the fiber during a nonwoven fabric manufacturing process such as a card opening process and a needle punch entanglement process. ,
The fibers after splitting are flattened, the fibers are easily broken in the direction of the relatively flat splitting surface, and the texture becomes soft.

Various additives can be blended and used in the bonded composite staple fiber as required. For example, catalysts, color inhibitors, heat-resistant agents, flame retardants, optical brighteners,
Matting agents, coloring agents, gloss improving agents, antistatic agents, fragrances, deodorants, antibacterial agents, anti-mite agents, inorganic fine particles and the like may be included. Further, the additives may be blended in either one of the polymer A and the polymer B, or both.

The nonwoven fabric used in the method of the present invention may be of the above-mentioned bonded type composite staple fiber, having an appropriate thickness and fullness, and having a soft texture, and the thickness of the nonwoven fabric is a leather-like sheet obtained. Can be arbitrarily selected depending on the use and the like, and is not particularly limited.
It is preferably about 3.0 mm,
More preferably, it is about mm. The apparent density of the nonwoven fabric is preferably 0.1 to 0.6 g / cm ³ in order to obtain a leather-like sheet having a soft texture,
More preferably, it is 0.15 to 0.55 g / cm ³ . When the apparent density is greater than 0.6 g / cm ³ ,
The resulting sheet tends to have a rubber-like texture.
On the other hand, if the apparent density is less than 0.1 g / cm ³ , the resilience and the feeling of waist are inferior, and the texture tends to be impaired.

The nonwoven fabric used in the method of the present invention is subjected to a treatment such as adhesion of a known compound such as a silicone-based or fluorine-based oil agent, a water-repellent agent, a softening agent, an antistatic agent, a light-resistant stabilizer, or an ultraviolet absorber. It can be carried out. In addition, other fibers may be added to the nonwoven fabric in addition to the above-described bonded staple fibers. Examples of the fiber entanglement method used when manufacturing the nonwoven fabric include a needle punch method and a water entanglement method.
A three-dimensional entangled nonwoven fabric more similar to a leather-like sheet is obtained, and the thickness is 1.0 m, which can be used for sports shoes, etc.
This is preferable because nonwoven fabrics of m or more can be easily treated.

The elastic polymer used in the method of the present invention comprises:
What is necessary is just a polymer elastic body that has been conventionally used when producing a leather-like sheet. Examples of such a polymer elastic body include a polyurethane resin, an acrylic resin, a polyamide resin such as a polyamide elastomer, a polyester resin such as a polyester elastomer, a polystyrene resin having elasticity, and a polyolefin resin having elasticity. Of these, polyurethane-based resins and acrylic resins are preferably used because they give the leather-like sheet obtained an excellent texture.

As a method for applying the resin, a so-called wet coagulation method in which a non-woven fabric is impregnated with a dimethylformamide solution such as polyurethane and wet coagulation and dewatering in water, or hot air, steam, microwave, hot water A preferred example is an emulsion method in which the resin is solidified or gelled and dried by any method such as a bath. If the wet coagulation method is adopted, a more natural leather-like texture can be obtained. Emulsions such as polyurethane emulsions and acrylic emulsions,
In particular, if an aqueous emulsion dispersed only with water is used, the leather-like sheet obtained by the method of the present invention can be produced without using an organic solvent, and furthermore, a method for producing a leather-like sheet with less environmental load. Is preferable.

When these emulsions have a thermosensitive gelling property, the emulsion particles can be thermogelled without causing migration and can be uniformly applied. Emulsions are used as emulsifying surfactants with H
A thermosensitive gelling property can be obtained by emulsifying with a nonionic surfactant having a low LB, or by adding a substance called a migration inhibitor to the emulsion as a thermosensitive gelling agent. Examples of the heat-sensitive gelling agent to be added include, for example, inorganic salts such as calcium chloride and a polyethylene glycol-type nonionic surfactant, polyvinyl methyl ether, polypropylene glycol, a silicone polyether copolymer, and a polysiloxane.
One or more of these can be used.

The leather-like sheet comprising the fibrous base and the elastic polymer is produced in the following steps (1) → (2) → (3) or (1) → (3) → (2). Can be.
In particular, if the steps (1), (2), and (3) are performed in this order, the splitting is performed after the elastic polymer is applied to the nonwoven fabric, so that a leather-like sheet having a softened and excellent texture can be obtained. preferable. Further, by performing a heat press treatment using a hot roll or the like after the step (1) or the step (2), it is possible to obtain a desired specific gravity or to form a smooth surface. (1) In a fiber composed of two types of polymer components having different A and B, the total number of laminated layers of component A and component B is 5 or more, and component A has a cross-sectional structure in which component B is coated. And, the ratio (t / d) of the minimum thickness (t) of the component A of the covering portion to the maximum fiber diameter (d) was in the range of 0.005 to 0.03, and the composite staple fiber was constituted. A step of manufacturing a nonwoven fabric, (2) a step of providing a polymer elastic body to the nonwoven fabric, and (3) a component A and a component B at 100 to 160 ° C.
Splitting with hot water,

Alternatively, when a dyed leather-like sheet is obtained, the process can be streamlined by splitting the joined staple fibers at the same time during the dyeing step. In this case, it is also possible to obtain a leather sheet by separately dyeing the leather-like sheet obtained by splitting with hot water again in hot water, but from the viewpoint of streamlining the process. This is not a preferable method in that the heating time is prolonged and the mechanical properties are easily reduced. In this case, it is preferable that the fiber component A and / or B used is a polyester polymer that can be dyed with a disperse dye. Such a dyed leather-like sheet can be manufactured, for example, by a method in which the above step (3) is replaced with the following step (3 ′). And it can manufacture in order of the following process (1)->(2)-> (3). (1) In a fiber composed of two types of polymer components having different A and B, the total number of laminated layers of component A and component B is 5 or more, and component A has a cross-sectional structure in which component B is coated. And, the ratio (t / d) of the minimum thickness (t) of the component A of the covering portion to the maximum fiber diameter (d) was in the range of 0.005 to 0.03, and the composite staple fiber was constituted. A step of producing a nonwoven fabric, (2) a step of providing a polymer elastic material to the nonwoven fabric, and (3 ′) a temperature of 100 ° C to 16 ° C using a disperse dye.
Splitting the fiber component A and the component B during the dyeing treatment at 0 ° C. or during the reduction treatment performed after the dyeing treatment,

The weight ratio between the nonwoven fabric and the elastic polymer constituting the obtained leather-like sheet can be appropriately selected depending on the application, but it is generally preferably from 5 to 150% by weight based on the weight of the nonwoven fabric. More preferably, it is from about 120% by weight to about 120% by weight, and further preferably from 30 to 100% by weight. If the content is less than 5% by weight, problems such as falling off of fibers, extension of nonwoven fabric during processing, and lack of fullness of the obtained sheet occur due to lack of a binder effect by the polymer elastic body. Sheet texture tends to be poor. On the other hand, if it exceeds 150% by weight, the obtained sheet tends to be hard and the texture of the leather-like sheet tends to be poor.

In the method of the present invention, splitting in hot water or a hot water liquid to which a disperse dye is added becomes possible as a method of splitting the components A and B. A leather-like sheet substrate can be obtained without generating a waste liquid. The splitting treatment in this case can be performed using a liquid jet dyeing machine such as circular or a hot water bath, but the point of using hot water of 100 ° C. or more and the flexibility of the obtained leather-like sheet base material It is preferable to use a circular dyeing machine or the like because of its superiority.

An important point in the present invention is the temperature at which the splitting treatment with hot water is performed.
It needs to be 60 ° C. Fibers and resins forming the leather-like sheet base material are easily softened in hot water of 100 ° C. or higher in a pressurized system, and the component A is combined with the component A by a synergistic effect of this and physical force in a circular dyeing machine. Despite being coated, the splitting proceeds, and it is considered that the soft leather-like sheet base material has an excellent texture due to the relaxing effect. Therefore, if the treatment temperature is lower than 100 ° C., the splitting of the fiber component of the obtained sheet base material does not proceed, resulting in poor flexibility, or a very long time treatment to develop the same flexibility. Will be required. When the processing temperature is 100 to 160 ° C., the fiber can be split by performing the processing for about 10 minutes to 1 hour. For the above reasons, the higher the processing temperature, the more the leather-like sheet substrate obtained by the splitting progress and relaxation effect tends to have a softer and more uniform texture. However, when the temperature is higher than 160 ° C., the resin component or the fiber component constituting the sheet base material is deteriorated and the texture is deteriorated,
Physical properties may be reduced. When dyeing with a disperse dye is performed at the same time, it is preferable to perform the treatment at a temperature of 120 ° C to 150 ° C in view of uneven dyeing and fastness of dyeing.
Further, as an auxiliary means for further progressing the splitting, a physical force after the formation of the nonwoven fabric, that is, a processing method of performing rubbing or crushing, or performing a water jet flow treatment can be used. .

The leather-like sheet obtained by the method of the present invention has a moderate flexibility and a sense of fulfillment, and includes mattresses, bag lining materials, clothing interlining, shoe cores, cushioning materials, automobile interior materials, wall materials, It can be suitably used for carpets and the like. Further, by forming a resin coating layer by applying polyurethane or the like to one surface by a known method, it can be suitably used as artificial leather with silver used for sports shoes, men's shoes, bags and the like. In this case, when polyurethane or the like is applied to the skin layer using an aqueous emulsion, artificial leather with silver can be obtained without using an organic solvent. Also, suede-like artificial leather can be obtained by buffing the surface with emery paper or the like. Of course, the formation of the resin coating layer and the buffing treatment can be performed prior to the hot water treatment.

[0033]

EXAMPLES The method of the present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. In the following examples, the following methods were used to evaluate the state of the split state after passing the card, the needle punch, and the splitting treatment of the bonded composite staple fiber obtained by combining various high-molecular polymers.

[Maximum diameter of fiber (d) and coating thickness (t)]: From a photograph of a cross section of a fiber tow prepared with a razor and cut with a scanning electron microscope (1000 to 20000 times), the maximum diameter of the fiber and polyester The coating thickness of the component (the thickness at the thinnest portion of the coating portion) was determined, and t / d was determined. Observation of five fibers selected at random, t / d
Was calculated.

[Card processing passability]: A web was made through a miniature card so as to have a basis weight of 50 g / m ^2, a tow was made from the fiber taken out of the fleece, and cut with a razor to cut about 400 side faces. The state was observed with a scanning electron microscope, the number of cracks was counted, and the splitting ratio was determined by the following equation. Splitting rate (%) = (number of broken fibers / total number of fibers) x 1
00 (%)

[Needle punching treatment passability]; card,
The fleece obtained through the process of the cross wrapper is appropriately laminated, a needle punch of 800 pieces / cm ² is performed, a tow is formed from the taken out fiber, and cut to about 400 pieces.
The state of the side surface of the book was observed by a scanning electron microscope for the state of the inside of the web, and the broken pieces were counted, and the splitting ratio was determined by the following equation. Splitting rate (%) = (number of broken fibers / total number of fibers) x 1
00 (%)

[Split treatment] The split ratio was determined by the following formula from observation of a scanning electron microscope photograph of the leather-like sheet obtained by splitting treatment with hot water. Splitting rate (%) = (number of broken fibers / total number of fibers) x 1
00 (%)

Example 1 Using polyethylene terephthalate as the polymer component A and nylon 6 as the polymer component B, the weight ratio was 66/3.
After alternately arranging 11 layers at a ratio of 4, the mixture was discharged from a die and spun. The melt viscosity during spinning is 100
They were 0 poise and 1200 poise. After spinning, stretch,
A mechanical crimp was applied and then cut to 51 mm to obtain a composite staple fiber having a cross-sectional shape of the type shown in FIG. The fineness of the obtained composite staple fiber is 3.3 dtex, and the ratio (t / t) of the maximum diameter (d) of the fiber to the minimum thickness (t) of the fiber.
d) was 0.007. The ratio of the length to the width in the fiber cross section of each layer constituting the fiber is 6.7 on average.
And the average fineness of each layer was 0.30 dtex.

Using this composite staple fiber, a card was processed to produce a web. After the card processing, the splitting of the fiber was 1.8%. No process trouble occurred in the web preparation, and good passability was exhibited. Further, a needle punching treatment was performed, but the process passability was good. The splitting of the fiber at this point was 2.6%. The nonwoven fabric thus obtained was impregnated with an aqueous polyurethane emulsion bondic 1310NSA (polyurethane emulsion manufactured by Dainippon Ink and Chemicals, Inc.) so that the solid content after drying was 80% by weight of the nonwoven fabric.
After drying, the surface was smoothed and the specific gravity was adjusted by a hot press at 165 ° C.

Further, using a circular dyeing machine, 12
The sheet was treated in hot water at 0 ° C. for 40 minutes and dried to obtain a sheet substrate. The obtained sheet was a leather-like sheet having an excellent texture. As a result of cross-sectional observation, the splitting of the fiber was 92%. Further, a 50-μm-thick polyurethane film colored with a white pigment by a release paper surface was adhered to one surface of the obtained sheet using an aqueous polyurethane-based adhesive to obtain an artificial leather with silver. The resulting artificial leather with silver tone was soft and excellent in texture.

Comparative Example 1 Using polyethylene terephthalate as the polymer component A and nylon 6 as the polymer component B, the weight ratio was 67/3.
After alternately arranging 11 layers at a ratio of 3, the mixture was discharged from a die and spun. The melt viscosity during spinning is 400
Poise and 2000 poise. After spinning, it was stretched, mechanically crimped, and then cut to 51 mm to obtain a composite staple fiber having a cross-sectional shape of the type shown in FIG. The fineness of the obtained composite staple fiber is 3.3 dtex, and the ratio (t / t) of the maximum diameter (d) of the fiber to the minimum thickness (t) of the fiber.
d) was 0.055.

Using this composite staple fiber, card processing was performed to produce a web. After the card processing, the fiber splitting was 0.3%. No process trouble occurred in the web preparation, and good passability was exhibited. Further, a needle punching treatment was performed, but the process passability was good. The splitting of the fiber at this point was 0.7%. The nonwoven fabric thus obtained was impregnated with an aqueous polyurethane emulsion Bondic 1310NSA (a polyurethane emulsion manufactured by Dainippon Ink and Chemicals, Inc.) so that the solid content after drying was 80% by weight of the nonwoven fabric.
After drying, the surface was smoothed and the specific gravity was adjusted by a hot press at 165 ° C.

Further, using a circular dyeing machine, 12
The sheet was treated in hot water at 0 ° C. for 40 minutes and dried to obtain a sheet. The obtained sheet was clearly harder than Example 1 and had a poor texture. As a result of cross-sectional observation, the splitting ratio of the fibers was 45.5%. An artificial leather with silver was obtained by laminating a 50-μm-thick polyurethane film colored with white pigment on a release paper surface in the same manner as in Example 1 using an aqueous adhesive in the same manner as in Example 1. Was hard and had a grainy leather-like sheet-like material having a poor texture compared to Example 1.

Comparative Example 2 Using polyethylene terephthalate as the polymer component A and nylon 6 as the polymer component B, the weight ratio was 66/3.
After alternately arranging 11 layers at a ratio of 4, the mixture was discharged from a die and spun. The melt viscosity during spinning is 110
They were 0 poise and 1200 poise. After spinning, stretch,
A mechanical crimp was applied and then cut to 51 mm to obtain a composite staple fiber having a cross section of the type shown in FIG. The fineness of the obtained composite staple fiber is 3.3 dtex, the maximum diameter (d) of the fiber and the minimum thickness (t) of the coated portion of the fiber.
Was 0.003 (t / d).

Using this composite staple fiber, card processing was performed to produce a web. Immediately after the card processing, the fiber splitting was 40.5%, and one hour after the web production, a large amount of nep was generated. However, the card device was clogged, and a good fleece could not be obtained. Further, the fleece obtained within 2 hours of card processing was subjected to needle punching, but showed a behavior of slightly expanding in the lateral direction due to punching. The splitting of the fiber at this point was 55.2%. An aqueous polyurethane emulsion bondic 1310N was added to the nonwoven fabric thus obtained.
SA (Dainippon Ink and Chemicals, a polyurethane emulsion) was impregnated so that the solid content after drying was 80% by weight of the nonwoven fabric, and after drying, surface smoothing and specific gravity matching were performed by a 165 ° C hot press. .

Further, using a circular dyeing machine, 12
The sheet was treated in hot water at 0 ° C. for 40 minutes, and dried to obtain a sheet. The obtained sheet substrate had a leather-like texture, but contained a large amount of NEP, and was inferior to Example 1 in texture and surface smoothness. As a result of cross-section observation, the splitting of the fiber was 95.5%. Further, a 50-μm-thick polyurethane film colored with a white pigment on a release paper-making surface as in Example 1 was adhered to one surface of the obtained sheet using an aqueous adhesive to obtain artificial leather with silver.
The obtained artificial leather with silver tone was soft and excellent in texture, but was slightly inferior to Example 1 in terms of the texture.

Example 2 Using polybutylene terephthalate as the polymer A and nylon 66 as the polymer component B, the weight ratio was 35/65.
, And alternately arranged in 9 layers, and then spun by discharging from a die. The melt viscosities during spinning were 1000 poise and 1200 poise, respectively. After spinning, it was stretched, mechanically crimped, and then cut to 51 mm to obtain a composite staple fiber having a cross-sectional structure of the type shown in FIG. The fineness of the obtained composite staple fiber was 4.0 decitex, and the ratio (t / d) of the maximum diameter (d) of the fiber to the minimum thickness (t) of the fiber was 0.02. The ratio of the length to the width in the fiber cross section of each layer constituting the fiber was 6.8 on average, and the average fineness of each layer was 0.44 dtex.

Using this composite staple fiber, card processing was performed to produce a web. After the card processing, the fiber split was 1.3%. No process trouble occurred in the web preparation, and good passability was exhibited. Further, a needle punching treatment was performed, but the process passability was good. The splitting of the fiber at this point was 2.2%. The nonwoven fabric thus obtained is impregnated with aqueous polyurethane emulsion Resamine W-1800 (polyurethane emulsion manufactured by Dainichi Seika Kogyo Co., Ltd.) so that the solid content after drying is 60% by weight of the nonwoven fabric, and after drying, 1
Surface smoothing and specific gravity matching were performed by a 60 ° C. hot press.

Further, using a circular dyeing machine, a disperse dye Kayalon Polyester Red AUL-S manufactured by Nippon Kayaku Co., Ltd. was used at a concentration of 1.5% owf and a bath ratio of 1/20 with a circular dyeing machine at 130 ° C. The staining was performed for a minute. The sheet substrate obtained after drying was a leather-like sheet having an excellent texture. As a result of cross-section observation, the splitting of the fiber was 94%. Finishing was performed by buffing with emery pepper to obtain a suede-like artificial leather. The obtained suede-like artificial leather was excellent in appearance and texture, and no uneven dyeing of fibers was observed.

Comparative Example 3 The same polymer as in Example 2 was used in the same weight ratio as Polymer Component A and Polymer Component B except that the nozzles were changed. Bonded composite spun staple fibers were alternately arranged in a petal pattern composed of layers. The fineness of the obtained composite staple fiber was 4.0 dtex, and the ratio (t / d) of the maximum diameter (d) of the fiber to the minimum thickness (t) of the component A was 0.022.

Using this composite staple fiber, a card was processed to produce a web. After the card processing, the splitting of the fiber was 3.7%. There was no process trouble in the production of the web, and good transmissivity was shown. Further, a needle punching treatment was performed, but the process passability was good. The splitting of the fiber at this point was 4.6%. The nonwoven fabric thus obtained is impregnated with aqueous polyurethane emulsion Resamine W-1800 (polyurethane emulsion manufactured by Dainichi Seika Kogyo Co., Ltd.) so that the solid content after drying is 60% by weight of the nonwoven fabric, and after drying, 1
Surface smoothing and specific gravity matching were performed by a 60 ° C. hot press.

Further, using a circular dyeing machine, a disperse dye Kayalon Polyester Red AUL-S manufactured by Nippon Kayaku Co., Ltd. was used at a concentration of 1.5% owf and a bath ratio of 1/20 with a circular dyeing machine at 130 ° C. The staining was performed for a minute. The sheet obtained after drying was inferior to Example 2 in terms of flexibility and texture. As a result of cross-section observation, the splitting of the fiber was 39%. Finished by buffing to obtain a suede-like artificial leather. The obtained suede-like artificial leather was inferior to Example 1 in terms of flexibility and texture as compared with Example 1. No uneven dyeing of the fiber was observed.

Comparative Example 4 An aqueous polyurethane emulsion Rezamin W-1800 was applied to the nonwoven fabric obtained in Example 2 in exactly the same manner as in Example 2.
(Polyurethane emulsion manufactured by Dainichi Seika Kogyo Co., Ltd.) was impregnated so that the solid content after drying was 60% by weight of the nonwoven fabric, dried, and then subjected to surface smoothing and specific gravity matching by a 160 ° C. hot press. Using a circular dyeing machine, a polyurethane emulsion impregnated non-woven fabric was dispersed with Nippon Kayaku's disperse dye Kayalon Polyester Red AUL-S by 1.5% owf.
The dyeing treatment was carried out for 40 minutes with a circular dyeing machine at 80 ° C., which was a lower temperature treatment than in Example 2, under the conditions of the concentration of 1 and the bath ratio of 1/20. The sheet substrate obtained after drying was a very hard sheet substrate as compared with the leather-like sheet substrate obtained in Example 2. As a result of cross-sectional observation, the splitting of the fiber was 11%.
In addition, a suede-like artificial leather was obtained by performing buffing treatment and finishing in the same manner as in Example 2, but the obtained suede-like artificial leather had a harder texture than that of Example 2 and was conspicuous in uneven dyeing. Met.

[0054]

According to the method of the present invention, excellent process passability is obtained.
Further, it is possible to obtain a leather-like sheet substrate having an excellent texture, which is composed of a nonwoven fabric composed of bonded composite staple fibers and a polymer elastic body, which can be easily split into ultrafine fibers in a hot water bath. .

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a cross section of a multi-layer bonded type composite staple fiber used in the method of the present invention.

FIG. 2 is a view showing another example of the cross section of the multilayer-bonded-type composite staple fiber used in the method of the present invention.

FIG. 3 is a diagram showing another example of a cross section of the bonded and joined composite staple fiber not belonging to the present invention.

[Explanation of symbols]

 1: Component A 2: Component B d: Maximum diameter of fiber t: Minimum thickness of component A

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) D06M 15/564 D06P 1/16 Z 4L041 D06P 1/16 3/32 B 4L047 3/32 3/82 H 3 / 82 D06M 9/10 F-term (reference) 3B154 AA07 AA08 AA17 AB22 BA07 BA25 BB12 BB43 BB49 BC01 BF01 BF06 BF29 DA19 DA21 4F055 AA01 BA11 EA04 EA05 EA07 EA13 EA14 EA24 FA15 GA03 HA03 BA031A02 DA03 AA14 AA18 AA20 AB34 BA08 CA07 4L033 AA05 AA07 AA08 AB07 AC11 AC15 CA50 4L041 AA07 BA04 BA05 BA09 BA11 BA34 BD11 BD15 CA06 CA13 CA21 CA25 CA36 CA38 DD01 DD06 EE07 EE08 4L047 AA27 AB02 BA03 CC02 CC16 DA00

Claims (4)

[Claims] In a method for producing a leather-like sheet substrate, the following steps (1) to (3) are carried out in the order of (1) → (2) →
(3) A method for producing a leather-like sheet substrate, which is performed in the order of (1) → (3) → (2). (1) In a fiber composed of two types of polymer components having different A and B, the total number of laminated layers of component A and component B is 5 or more, and component A has a cross-sectional structure in which component B is coated. And, the ratio (t / d) of the minimum thickness (t) of the component A of the covering portion to the maximum fiber diameter (d) was in the range of 0.005 to 0.03, and the composite staple fiber was constituted. A step of manufacturing a nonwoven fabric, (2) a step of providing a polymer elastic body to the nonwoven fabric, and (3) a component A and a component B at 100 to 160 ° C.
Splitting with hot water, 2. The method for producing a leather-like sheet substrate according to claim 1, wherein the following step (3 ′) is used instead of step (3).
Splitting the fiber component A and the component B during the dyeing treatment at 0 ° C. to 160 ° C. or during the reduction treatment performed after the dyeing treatment; 3. In the step of splitting the component A and the component B,
The method for producing a leather-like sheet substrate according to claim 1 or 2, wherein a jet dyeing machine is used. 4. A leather-like sheet substrate obtained by the production method according to claim 1.