JP2010248683A - Leather-like sheet-shaped product and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a leather-like sheet-shaped product having an elegant surface appearance, excellent abrasion resistance and flame resistance, and to provide a method for producing the same. <P>SOLUTION: The leather-like sheet-shaped product is composed of a nonwoven fabric having ultrafine fibers with a fiber length of not less than 2 cm which are entangled each other, containing 15 mass.% or less of a polymeric elastomer, and an organic or halogen based flame retardant. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a leather-like sheet having excellent flame retardancy and a method for producing the same.

  Leather-like seats have made use of their elegant surface appearance and flexibility, and have traditionally been used not only for clothing but also for materials and sundries, such as shoes, bags, gloves, vehicle seats and furniture overlays. Used for applications. Among them, in the field of interior coverings such as railroads, automobiles, airplanes, ships, etc., and interior furniture, wall materials, sofas, chairs, etc., in addition to excellent wear resistance, in terms of safety Excellent flame retardancy is required. Several methods have been proposed so far for imparting flame retardancy of leather-like sheets.

  For example, there is a post-processing method in which a leather-like sheet is manufactured and then impregnated with a flame retardant (see, for example, Patent Document 1). Although this method is simple, it is generally necessary to add a large amount of a flame retardant of 10 to 100% by weight in order to obtain the desired flame retardancy, and problems such as stickiness, texture hardening, and decrease in dyeing fastness There is. Furthermore, when the leather-like sheet base material is formed of ultrafine fiber bundles, most of the flame retardant is present on the outside of the ultrafine fiber bundle or on the outer surface of the elastic polymer, and the flame retardant is easy to drop off and is durable. It is difficult to obtain a certain flame retardant effect. Although a method of preventing the flame retardant from falling off with a binder is also conceivable, there are problems such as the loss of the flexibility required for the leather-like sheet and the inferior appearance quality because a sufficient raised state cannot be obtained.

  Also proposed are a method of laminating a woven or knitted fabric having flame retardancy on the back surface of a leather-like sheet substrate, and a method of producing a leather-like sheet substrate using fibers produced by adding flame-retardant fine particles. (For example, refer to Patent Document 2). Such a method is superior in terms of soft texture and durability as compared with the case where a flame retardant is applied in post-processing. However, when flame retardancy is imparted to ultrafine fibers, there are restrictions on the spinning temperature setting, polymer and flame retardant selection, etc. in terms of the stability of the flame retardant and polymer, and yarn breakage tends to occur, resulting in poor productivity. . In addition, the physical properties of the fiber are greatly lowered, and the surface fiber is dropped.

  On the other hand, a method is disclosed in which a surface layer is made of ultrafine thermoplastic synthetic fibers having a thickness of 0.5 dtex or less, and a phosphorus copolymer thermoplastic synthetic fiber is used for the underlying woven or knitted fabric and / or the back layer (for example, Patent Document 3). reference). However, in order to impart flame retardancy, it is necessary to relatively increase the ratio of the scrim and the back surface layer relative to the surface layer, and there is a problem that the scrim is exposed due to wear and the quality is greatly lowered. In particular, when the fiber length is short and the fiber strength is low (easy to break), the weight loss is increased, and the problem becomes remarkable.

  Furthermore, although a method using a polymer elastic body added with a flame retardant to a polymer elastic body contained in the entangled space of the nonwoven fabric constituting the leather-like sheet base material has been proposed (see, for example, Patent Document 4), it is generally sufficient. It is difficult to obtain a flame retardant effect, and there is a decrease in the degree of polymerization of the elastic polymer over time, which is not preferable. In this method, if the amount of the flame retardant added to the polymer elastic body is increased in order to increase the flame retardant effect, the texture of the leather-like sheet becomes hard and the sense of quality is lost. Furthermore, if the polymer elastic body is increased in order to increase the flame retardant, the flame retardancy is rather lowered.

  Therefore, a method has been proposed in which flame retardancy is achieved by a scrim made of flame retardant fibers and a nonwoven fabric disposed on the back layer, and a flammable polymer elastic body is suppressed to 5 to 20% by weight (for example, (See Patent Document 5). Although pilling is likely to occur with a decrease in the amount of use of the elastic polymer, this is suppressed by reducing the fiber strength and promoting cutting. However, there is a problem in that wear loss due to friction increases due to fiber cutting, and there is no napping and the scrim is exposed. This tendency is particularly remarkable when the fiber length is short.

  On the other hand, in the case of a fiber having a long fiber length and sufficient strength, there is no problem of wear loss, but pilling is likely to occur with a decrease in the amount of use of the polymer elastic body, thereby reducing the surface quality. Therefore, from the viewpoint of flame retardancy, while making the polymer elastic body a relatively small amount of 3 to 15% by weight, the sea-island composite fiber is sufficiently intertwined, and further, the area shrinkage of 30% or more is performed to improve the fluff density. (For example, refer to Patent Document 6). However, it is only the state of the composite fiber that is sufficiently entangled, and after the sea component is removed, the ultrafine fiber bundles are merely entangled. Therefore, the ultrafine fibers are not intertwined, and the problem that pilling is likely to occur cannot be solved.

  As described above, a leather-like sheet having wear resistance and flame retardancy that satisfies pilling and weight loss while maintaining an elegant surface appearance and flexibility has not been obtained.

JP-A-60-215878 JP 2002-294571 A JP 2004-169197 A Japanese Patent Laid-Open No. 7-18484 International Publication No. 2005/11300 Pamphlet JP 2004-131875 A Japanese Patent Publication No. 44-18369 JP 54-116417 A

  An object of the present invention is to obtain a leather-like sheet having an elegant surface appearance and excellent wear resistance and flame retardancy.

  That is, the present invention includes a nonwoven fabric in which ultrafine fibers having a fiber length of 2 cm or more are entangled with each other, the polymer elastic body is 15% by mass or less, and contains an organic phosphorus flame retardant or a halogen flame retardant. It is a leather-like sheet.

The present invention is also a method for producing the leather-like sheet of the present invention,
A step of forming a non-woven fabric by needle punching a very fine fiber-expressing fiber capable of expressing an ultra-fine fiber,
A step of expressing an ultrafine fiber from the ultrafine fiber expressing fiber,
A method for producing a leather-like sheet-like material comprising a step of performing high-speed fluid treatment at a pressure of 10 MPa or more on a nonwoven fabric expressing the ultrafine fibers in this order.

  The leather-like sheet-like material of the present invention has an elegant surface appearance, and is excellent in flame retardancy while having wear resistance such as suppression of weight loss and anti-pilling property.

  The single fiber diameter of the ultrafine fiber is preferably 1 to 10 μm. The thickness is preferably 1 μm or more, more preferably 2 μm or more, and further preferably 3 μm or more, so that light resistance and wear loss due to cutting can be suppressed. Moreover, by making it preferably 10 μm or less, more preferably 7 μm or less, and even more preferably 5 μm or less, it is excellent in surface touch and an original elegant appearance of a leather-like sheet is obtained.

  As the fiber length of the ultrafine fibers, it is necessary that the main fibers constituting the nonwoven fabric be 2 cm or more. By setting it to 2 cm or more, preferably 5 cm or more, wear loss, that is, fiber dropout due to friction can be suppressed, and deterioration of appearance quality can be prevented. In addition, if it is 2 cm or more, it may be a long fiber, and specifically, the leather-like sheet-like material of the present invention may be produced based on a long-fiber nonwoven fabric. It is preferable to cut appropriately with a needle punch or the like within such a range. In order to obtain a more excellent quality, it is preferably 10 cm or less, more preferably 8 cm or less, and further preferably 6 cm or less.

  It is important that the ultrafine fibers are intertwined with each other to form a nonwoven fabric. By adopting a structure in which ultrafine fibers are entangled with each other, anti-pilling properties can be obtained even if a large amount of polymer elastic body is not included. Of the conventional leather-like sheets made of ultrafine fibers, those having a fiber length of 2 cm or more generally have a structure in which the ultrafine fibers are entangled in a bundle of fibers. In the conventional leather-like sheet, there is a problem that the anti-pill property is lowered when the amount of the polymer elastic body is reduced, but in the present invention, the anti-pill property is greatly improved by the high degree of fiber entanglement. In this way, the amount of the elastic polymer can be greatly reduced as compared with the prior art. In addition, the state of the fiber bundle may be included as long as the effect of the present invention is not impaired.

  The ultrafine fibers in the leather-like sheet-like material of the present invention are preferably made of a thermoplastic resin and made of inelastic fibers. Specifically, fibers made of polyester, polyamide, polypropylene, polyethylene, etc. are preferably used from the viewpoint of physical properties and productivity, and fibers made of polyester or polyamide are particularly preferably used from the viewpoint of excellent dyeability and quality. Elastic fibers such as polyether ester fibers and polyurethane fibers such as so-called spandex are not preferable. The polyester is not particularly limited as long as it can be fiberized. Specifically, for example, polyethylene terephthalate, polytrimethylene terephthalate, polytetramethylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalenedicarboxylate, polyethylene-1,2-bis (2- Chlorophenoxy) ethane-4,4′-dicarboxylate and the like. Of these, the most commonly used polyethylene terephthalate or a polyester copolymer mainly containing ethylene terephthalate units is preferably used. Examples of the polyamide include polymers having an amide bond such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and the like. Of these, nylon 6 and nylon 66, which are generally used, are preferably used.

  The leather-like sheet material of the present invention includes a non-woven fabric in which ultrafine fibers having a fiber length of 2 cm or more are entangled with each other, and the content thereof is determined from the mass of the leather-like sheet material of the present invention. 50 mass% or more is preferable with respect to the mass which deducted the mass of a flame retardant or a halogenated flame retardant.

  The leather-like sheet-like product of the present invention mainly comprises a nonwoven fabric in which ultrafine fibers having a fiber length of 2 cm or more are entangled with each other, but preferably contains a woven or knitted fabric in addition to the nonwoven fabric. By doing so, it is possible to obtain higher morphological stability suitable for applications such as a seat upholstery material. In particular, in the present invention, in order to improve the shape stability which is reduced in relation to the content of the polymer elastic body, it is a preferable aspect to laminate the woven or knitted fabric.

  Woven knitted fabric is a general term for woven fabrics or knitted fabrics. Examples of woven fabrics include plain weave, twill weave and satin weave, and examples of knitted fabric include circular knitting, tricot, raschel and the like. From the viewpoint of production cost, plain weave is preferred.

  The woven or knitted fabric may be contained in one or several kinds within a range not impairing the object of the present invention. The total mass of the content is determined from the mass of the leather-like sheet material of the present invention to the polymer elasticity. It is preferable to keep it to 50% by mass or less based on the mass obtained by subtracting the mass of the body and the organic phosphorus flame retardant or halogen flame retardant.

  The material of the woven or knitted fabric is not particularly limited, but the same material as the ultrafine fiber can be used.

  It is important that the content of the polymer elastic body in the leather-like sheet of the present invention is 15% by mass or less based on the mass of the leather-like sheet. By setting the content of the polymer elastic body to 15% by mass or less, preferably 5% by mass or less, more preferably 2% by mass or less, excellent flame retardancy can be exhibited. In addition, by using a leather-like sheet-like material made of a substantially fibrous material that does not contain 1% by mass or less of a polymer elastic body, particularly excellent flame retardancy can be exhibited.

  The polymer elastic body in the present invention is a polymer having rubber elasticity that expands and contracts. For example, a polyurethane elastomer, a polyester-based thermoplastic elastomer, a polyamide-based thermoplastic elastomer, a styrene-isoprene block copolymer is used. Examples include elastic hydrogenated products, acrylic rubber, natural rubber, styrene butadiene rubber (SBR), nitrile rubber (NBR), polychloroprene, polyisoprene, and isobutylene isoprene rubber. Polyurethane elastomers are preferred from the standpoint of wear.

  As the polymer elastic body, either a non-porous or porous polymer elastic body can be used, but a non-porous polymer elastic body is preferable in that higher flame retardancy can be exhibited. .

  It is important that the leather-like sheet material of the present invention contains an organic phosphorus flame retardant or a halogen flame retardant. These flame retardants can improve the flame retardancy. From the viewpoint of reducing the environmental load, an organic phosphorus flame retardant is preferable. Examples of the organic phosphorus flame retardant include guanidine phosphate, phosphate carbanate, phosphate ester, aromatic condensed phosphate ester, phosphate amide, and ammonium phosphate. On the other hand, a halogen-based flame retardant is preferable in order to obtain higher flame retardancy. In particular, in order to achieve both flexibility and flame retardancy of V-0 or VTM-0 or higher as defined in UL94, the above-described combination of a leather-like sheet material substantially made of a fiber material and a halogen-based flame retardant is preferable. . Examples of the halogen flame retardant include chlorine and bromine compounds. For example, brominated flame retardants such as decabromodiphenyl ether, pentabromobenzene, tetrabromobenzene, and brominated polystyrene, and chlorinated flame retardants such as chlorinated paraffin. Among them, non-decabrominated bromobenzene-based flame retardants can be preferably applied to reduce the environmental load.

  The organophosphorus flame retardant or halogen flame retardant is preferably selectively present on the back surface. By doing so, the sticky feeling is further reduced, and a more excellent surface quality appearance can be obtained. Examples of the flame retardant in such an embodiment include guanidine phosphates, phosphate carbanates, phosphate esters, aromatic condensed phosphate esters, phosphate ester amides, and flame retardants such as chlorine and bromine compounds. Can be mentioned.

  Moreover, in order to improve a flame retardance further, a flame retardant can be added in the fiber which comprises a nonwoven fabric and a woven / knitted fabric, or a flame retardant component can also be copolymerized. Examples of the flame retardant in that case include phosphorus-containing compounds such as oxaphospholane, phosphinic acid derivatives, phosphaphenanthrene derivatives, and phosphoric acid triesters. However, the fiber containing the flame retardant has a problem that the spinning stability is inferior, and the fiber is also cut to increase the weight loss. In the present invention, even a fiber that does not contain a flame retardant has high flame retardancy, and therefore, it is a preferred embodiment that it is a leather-like sheet made of fibers that do not contain a flame retardant.

As content of the organophosphorus flame retardant or the halogen flame retardant with respect to the leather-like sheet material, 0.5 to 15% by mass is preferable in the case of an immersion treatment such as a pad method. By setting the content to 0.5% by mass or more, more preferably 1.0% by mass or more, and still more preferably 2.0% by mass or more, good flame retardancy can be obtained. Further, by setting the amount to 15% by mass or less, more preferably 12% by mass or less, further preferably 10% by mass or less, and further preferably 5% by mass or less, the stickiness or texture of the flame retardant is further improved, and the napped quality of the surface is improved. Reduction can be suppressed. Moreover, 20-300 g / m < ² > is preferable in the case of the coating process to the back surface of a leather-like sheet-like material. Good flame retardance can be obtained by setting it as 20 g / m < ² > or more. Moreover, a softer texture can be obtained by setting it as 300 g / m < ² > or less, More preferably, it is 200 g / m < ² > or less, More preferably, it is 100 g / m < ² > or less.

  In the leather-like sheet-like material of the present invention, it is preferable that at least one surface has napping. By doing so, a so-called suede-like or nubuck-like elegant appearance and feel can be obtained.

The apparent density of the leather-like sheet-like material of the present invention is usually 0.20 to 0.80 g / cm ³ and preferably 0.40 to 0.70 g / cm ³ . By setting it to 0.40 g / cm ³ or more, more preferably 0.42 g / cm ³ or more, better flame retardancy and wear resistance can be obtained. Moreover, by setting it as 0.70 g / cm < ³ > or less, More preferably, it is 0.60 g / cm < ³ > or less, A texture is soft and the workability to various uses can be maintained.

  The number of twists of the yarn in the woven or knitted fabric is preferably 1300 to 3000 T / m. By making it 1300 T / m or more, more preferably 1500 T / m or more, it is less likely to be damaged when the laminated integration with the nonwoven fabric is performed by a needle punch, and when it is performed by high-speed fluid treatment, it has an effect of excellent fluid permeability. Have. Moreover, manufacturing cost can be restrained by setting it as 3000 T / m or less.

Moreover, as a fabric weight of the leather-like sheet-like material of this invention, 150-550 g / m < ² > is preferable. By setting it to 150 g / m ² or more, more preferably 200 g / m ² or more, it is possible to obtain mechanical properties such as strength suitable for material use. Moreover, favorable molding processability can be obtained by setting it as 550 g / m < ² > or less, More preferably, it is 500 g / m < ² > or less, More preferably, it is 450 g / m < ² > or less.

  The leather-like sheet-like material of the present invention preferably has a weight loss of 20 mg or less when the napped surface is worn 20000 times in the abrasion test in the Martindale method. By setting the weight loss to 20 mg or less, more preferably 15 mg or less, and even more preferably 10 mg or less, it is hardly observed that fuzz adheres to clothes or the like in actual use, and there is no practical problem. On the other hand, the lower limit is not particularly limited, and a leather-like sheet-like product of the present invention can be obtained with almost no wear loss.

  The leather-like sheet-like material of the present invention preferably has a burning rate of 70 mm / min or less in a flammability test specified in JIS D 1201: 1998, and further flame retardant to such an extent that the burning rate cannot be measured. It is preferable that the combustion length is less than 51 mm and the combustion time is less than 60 seconds. As described above, such flame retardancy can be achieved by minimizing the content of the flame retardant and the polymer elastic body and further increasing the apparent density. By achieving such flame retardancy, it is possible to achieve both wear resistance, flexibility and flame retardancy, and it can be preferably used particularly for interior materials for vehicles such as car seats.

  The leather-like sheet of the present invention is preferably VTM-0 in the combustion test specified in UL94. In the conventional artificial leather, it was VTM-2, but in the present invention, VTM-0 can be achieved by a combination of the above-described fiber base material and flame retardant. In particular, by using a combination of a fiber base material substantially composed of a fiber material and a brominated flame retardant, it is possible to obtain a flame-retardant leather-like sheet-like material having high flame resistance and flexibility and excellent quality. . Such a flame-retardant leather-like sheet material having both high flame retardancy and flexibility and quality can be preferably used particularly as an exterior material for electrical appliances.

  Next, an example of the method for producing the leather-like sheet of the present invention will be described.

  As a method for producing the ultrafine fiber as described above, for example, a method of spinning the ultrafine fiber directly, a method of spinning the ultrafine fiber expression type fiber and then developing the ultrafine fiber, or the like can be employed. Examples of the ultrafine fiber-expressing fiber include sea-island fibers and split fibers. Among these, sea-island type fibers are preferable in that fibers having a small diameter can be stably obtained.

Examples of methods for obtaining sea-island type fibers include:
(1) A method of blending and spinning two or more polymers in a chip state,
(2) A method in which a polymer of two or more components is kneaded in advance to form a chip and then spun.
(3) A method of mixing and spinning two or more polymers in a melted state in a spinning machine pack using a static kneader or the like,
(4) A method of spinning using a die disclosed in Patent Document 7, Patent Document 8, and the like,
And so on. Especially, the method of said (4) is preferable at the point which can manufacture the ultrafine fiber of the stable fineness.

  The number of polymer species to be used in the sea-island fiber is preferably 2 to 3 components in consideration of spinning stability and dyeability, and in particular, the sea component is composed of 1 component and the island component is composed of 1 component. Is preferred.

  The mass ratio of the island component to the sea-island fiber is preferably 0.3 to 0.99. By setting it to 0.3 or more, more preferably 0.4 or more, and still more preferably 0.5 or more, it is possible to suppress the removal rate of sea components, and hence the manufacturing cost. Further, by setting the ratio to 0.99 or less, more preferably 0.97 or less, and even more preferably 0.8 or less, the merging of island components can be suppressed and stable spinning can be performed.

  The sea-island type fiber by the method (4) is, for example, a method in which an unstretched yarn spun at a spinning speed of usually 2500 m / min or less is taken out and then stretched by one to three stages by wet heat or dry heat, or both. A drawn yarn can be obtained by a method of drawing at a spinning speed of 4000 m / min or more.

  As an average single fiber diameter of a sea-island type fiber, 10-30 micrometers is preferable. By setting the thickness to 30 μm or less, more preferably 25 μm or less, the sea-island fibers can be entangled efficiently. Moreover, it can prevent that a fiber cuts in an entanglement process by setting it as 10 micrometers or more, More preferably, it is 15 micrometers or more.

  Next, the obtained ultrafine fiber or sea-island type fiber is formed into a web. As the method, in the case of a short fiber nonwoven fabric, a dry method using a card, a cross wrapper, a random weber or the like, or a wet method such as a papermaking method can be employed. In the case of a long-fiber nonwoven fabric, a spunbond method can be employed.

  Here, in the case where the woven or knitted fabric is included, it can be manufactured by a method of intertwining the nonwoven fabric and the woven or knitted fabric by needle punching or high-speed fluid treatment, or a method of bonding the nonwoven fabric and the woven or knitted fabric by adhesion. However, the former is preferable in that the texture is flexible. In the present invention, as a method for producing a nonwoven fabric, a method of using two types of entanglement methods of needle punch and high-speed fluid treatment in combination with entanglement of sea-island type fibers and ultrafine fibers, respectively, as described later is preferable. .

  In the production method of the present invention, the needle punch that entangles the sea-island type fiber does not serve as a temporary fixing for simply passing through the process, but has a role to sufficiently entangle the sea-island type fiber.

The needle is preferably a 1 barb type in terms of excellent surface quality. The driving density of the needle punch is preferably 500 / cm ² or more. More preferably 1000 / cm ² or more, and even more preferably 1500 / cm ² or more, good entanglement can be obtained.

The apparent fiber density of the web made of sea-island fibers after needle punching is preferably 0.12 to 0.30 g / cm ³ . By setting it to 0.12 g / cm ³ or more, more preferably 0.15 g / cm ³ or more, the fibers are entangled well and good values are obtained for physical properties such as tensile strength, tear strength, and abrasion resistance. . Further, by setting it to 0.30 g / cm ³ or less, more preferably 0.25 g / cm ³ or less, it is possible to suppress the occurrence of needle needle breakage, needle hole residue, and the like.

  In the spunbond method, a polymer is melted and discharged from a die to form a continuous filament, which is spun at a speed of 2000 to 8000 m / min by a traction action such as an ejector and collected on a moving collection device. A long fiber web can be obtained.

  The obtained long fiber web is preferably entangled without being wound from the viewpoint of cost, but may be wound once from the viewpoints of transportability, handleability, production speed adjustment, and the like. In the case of winding once, it is preferable to perform press processing under heating at 80 to 240 ° C. or perform needle punch processing similar to the above from the viewpoint of imparting a certain form stability. Especially, a needle punch is preferable at the point which is excellent in texture and quality.

  The web is preferably shrunk and further densified by dry heat treatment or wet heat treatment, or both.

  Next, the non-woven fabric made of sea-island fibers is made into an ultra-fine fiber nonwoven fabric by ultra-thinning treatment, and the ultra-fine fiber nonwoven fabric is entangled with each other by high-speed fluid treatment. The high-speed fluid treatment may be performed after the ultrafine processing, or the high-speed fluid processing may be performed simultaneously with the ultrafine processing. Further, high-speed fluid processing may be performed simultaneously with the ultrafine processing, and then further high-speed fluid processing may be performed. When the high-speed fluid treatment also serves as the ultrafine treatment, it is preferable to perform the high-speed fluid treatment at least after the ultrafine treatment is mostly completed in order to further entangle the ultrafine fibers. In order to entangle the fibers with each other by performing high-speed fluid processing after reliably miniaturizing, it is preferable to perform high-speed fluid processing after performing the ultra-fine processing in any case.

  Examples of the ultrathinning method include a mechanical method and a chemical method. The mechanical method is a method in which sea-island fibers are made ultrafine by applying a physical stimulus. Specifically, for example, in addition to the method of giving an impact such as the needle punch method and the water jet punch method as described above, a method of pressurizing between rollers, a method of performing ultrasonic treatment, and the like can be mentioned. Moreover, as a chemical method, the method of giving a change of swelling, decomposition | disassembly, melt | dissolution, etc. with a chemical | medical agent with respect to at least 1 component which comprises a sea island type fiber is mentioned, for example. In particular, the method of treating a sea-island fiber using an alkali-degradable polymer as a sea component with a weakly acidic to alkaline (pH 6 to 14) aqueous solution to make it ultrafine is preferable in terms of environmental protection without using an organic solvent.

  The weakly acidic to alkaline aqueous solution preferably contains an organic salt or an inorganic salt. Examples of organic salts or inorganic salts include alkali metal salts such as sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, and sodium hydrogen carbonate, and alkaline earth metal salts such as calcium hydroxide and magnesium hydroxide. It is done. Of these, sodium hydroxide is preferable in terms of price and ease of handling.

  Moreover, it is also preferable to add and use amines, such as a triethanolamine, a diethanolamine, a monoethanolamine, a weight loss promoter, a carrier, etc. in weakly acidic-alkaline aqueous solution.

  After the treatment with the weakly acidic to alkaline aqueous solution, it is preferable to dry after removing the remaining chemicals and decomposition products by neutralization and washing.

  As the high-speed fluid treatment, a water jet punch treatment using a water flow instead of an organic solvent is preferable in terms of the working environment.

  In the water jet punching process, water is preferably performed in a columnar flow state. The columnar flow is usually obtained by ejecting water from a nozzle having a diameter of 0.06 to 1.0 mm at an injection pressure of 1 to 60 MPa.

  The nozzle hole diameter is 1.0 mm or less, more preferably 0.15 mm or less, and even more preferably 0.14 mm, thereby improving the entanglement between the ultrafine fibers, and the nonwoven fabric or the leather-like sheet. Surface smoothness can also be improved. On the other hand, the occurrence of nozzle clogging can be suppressed by setting the thickness to 0.06 mm or more, more preferably 0.08 mm or more.

  Further, by setting the nozzle interval to 5 mm or less, more preferably 1 mm or less, generation of streaks can be suppressed and the nozzles can be made inconspicuous.

  The high-speed fluid treatment is preferably repeated several times in order to achieve uniform entanglement in the thickness direction and improve the smoothness of the surface of the nonwoven fabric and thus the leather-like sheet.

  Note that at least one process means that the process is performed by one nozzle head (one injector) including a nozzle plate having a plurality of nozzle holes. When processing is continuously performed with a plurality of nozzle heads, the number of times of the plurality of nozzle heads is processed, and the number is not counted once.

  A nozzle plate including nozzles having different hole diameters may be used, or nozzle plates having different configurations may be used in combination when processing a plurality of times.

  The jetting pressure of the fluid is appropriately selected according to the basis weight of the ultrafine fiber web to be treated, and the higher the basis weight, the higher the pressure is preferable, and 10 to 60 MPa is preferable. 10 MPa or more, more preferably 15 MPa or more, and even more preferably 20 MPa or more, so that the ultrafine fibers are highly entangled with each other to improve the apparent density and have high tensile strength, tear strength, wear resistance, and other physical properties. Can be obtained. In addition, by setting the pressure to 60 MPa or less, more preferably 40 MPa or less, and even more preferably 35 MPa or less, generation of fluff due to fiber cutting is prevented, and the nonwoven fabric and thus the leather-like sheet is prevented from becoming non-uniform. Can also be suppressed.

  In the case of ultrafine fibers obtained from sea-island type fibers, it is common that the ultrafine fibers are intertwined in a bundled fiber bundle, but by performing high-speed fluid treatment under the above conditions, the fiber bundles It is possible to obtain an ultrafine fiber nonwoven fabric in which ultrafine fibers are entangled with each other to such an extent that entanglement in this state is hardly observed. As a result, the ultrafine fiber bundle is intertwined, and in addition to this, the ultrafine fiber is intertwined with the ultrafine fiber in the ultrafine fiber bundle or other ultrafine fiber bundles, so that it is particularly resistant to wear. An excellent ultrafine fiber nonwoven fabric can be obtained. In addition, you may perform a water immersion process before performing a high-speed fluid process. Furthermore, in order to improve the quality of the surface of the nonwoven fabric, a method of relatively moving the nozzle head and the nonwoven fabric, a method of inserting a wire mesh between the nonwoven fabric and the nozzle, and performing a watering treatment can be performed.

  In addition, as a method of performing ultrafine treatment and high-speed fluid treatment at the same time, for example, a method of using sea-island fibers using a water-soluble polymer as a sea component, and removing sea components and entanglement of ultrafine fibers by a water jet punch , Using sea-island fibers using an alkali-soluble polymer as a sea component, and after decomposing the sea component through an alkali treatment liquid, performing a final removal of the sea component and entanglement treatment of ultrafine fibers by a water jet punch, Etc.

  When laminating a nonwoven fabric and a woven or knitted fabric, the laminating method is not particularly limited and can be performed by adhesion, entanglement, or the like. In this case, it can be carried out by needle punching or high-speed fluid treatment according to the method for producing the nonwoven fabric, but laminating by high-speed fluid treatment is particularly preferred because damage to the woven or knitted fabric can be prevented.

  In the case of applying a polymer elastic body, a porous material is obtained by wet coagulation of a solvent-based polymer elastic material. Obtainable.

  Here, it is preferable that the dispersion liquid of the water-dispersed polymer elastic body has a heat-sensitive gelling property in terms of easy texture adjustment. The heat-sensitive gelling property means a property that loses fluidity when heated and becomes a gel. Migration can be suppressed by impregnating the dispersion liquid of the water-dispersed polymer elastic body and then heating to cause gelation to lose the fluidity of the polymer elastic body. Thereby, it can suppress that a polymeric elastic body is unevenly distributed in a nonwoven fabric, and can obtain a favorable surface quality and a flexible texture. The thermal gelation temperature of the dispersion of the water-dispersed polymer elastic body is preferably 40 to 80 ° C. from the viewpoint of stable production. In adjusting the heat-sensitive gelation temperature, a heat-sensitive gelling agent or the like may be added, or a heat-sensitive gelling component may be introduced into the resin. Examples of the heat-sensitive gelling agent include polyoxyalkylene ether, polyoxyethylene alkyl allyl ether, polyoxyethylene-polyoxypropylene block polymer, polyoxyethylene acyl ester, polyoxyethylene polyaryl ether, and alkylene of alkylphenol-formalin condensate. Examples thereof include oxide adducts, nonionic surfactants, organopolysiloxane compounds, and the like.

  In addition, in the dispersion of the water-dispersed polymer elastic body, in addition to the heat-sensitive gelling agent, a crosslinking agent, a stabilizer, a penetrating agent, a thickener, a migration inhibitor, and the like within a range not impairing the effects of the present invention. May be added. In particular, a method of adding a thickener or a migration inhibitor is a preferred embodiment in order to prevent migration.

  After the dispersion of the water-dispersible polymer elastic body is applied, the nonwoven fabric containing the dispersion is heated to 70 to 200 ° C. with dry heat, hot water, hot water, normal pressure or high pressure steam, microwave, or the like. Gelling (solidification) treatment is preferable. For example, an apparatus for heating with steam includes an atmospheric steamer, a high temperature steamer, and the like.

  Next, when finishing in suede or nubuck, the surface is raised. As the raising method, buffing with a needle cloth raising or sandpaper can be adopted, but buffing is preferable because fine napping is formed and a uniform surface is obtained.

  In order to improve the quality, it is better to dye. The dyeing method is not particularly limited, and the dyeing machine to be used may be any of a liquid dyeing machine, a thermosol dyeing machine, a high-pressure jigger dyeing machine, etc., but it is liquid in that the texture of the obtained leather-like sheet is excellent. It is preferable to dye using a flow dyeing machine.

  Next, a phosphorus-based or halogen-based flame retardant is applied. The application method is not particularly limited, and examples thereof include an impregnation method, a bath exhaust method, and a method of applying to the back surface. Examples of the impregnation method include a method of dipping in a pad solution, squeezing with a mangle at a pickup rate of 5 to 100 wt%, and drying at a temperature of 80 to 180 ° C. with a net dryer or a pin tenter. Examples of the exhaustion method in the bath include a method in which a flame retardant is added with a liquid dyeing machine and the like, followed by treatment at 100 to 150 ° C. and then drying. Moreover, as a method of apply | coating to a back surface, after applying resin components, such as a flame retardant and a binder, with a spray, a rotary screen, a knife coater, a gravure coater, etc., the method of drying similarly to the above is mentioned. In the present invention, the impregnation method is preferably employed in that it can be produced simply and stably, and the method of applying to the back surface is preferably employed in that it can further suppress poor quality and stickiness due to the adhesion of the flame retardant to the napped surface. The

  Hereinafter, the present invention will be described in detail with reference to examples. In addition, the following method was used for the measuring method of each physical-property value in an Example.

(1) Fiber basis weight, fiber apparent density The fiber basis weight (g / m ² ) was measured by the method described in JIS L 1096 8.4.2 (1999). Also, the thickness (mm) was measured at 10 locations at random using a dial thickness gauge (trade name “Peacock H”, manufactured by Ozaki Mfg. Co., Ltd.), the average value was obtained, and the third decimal place was rounded off. Was used to determine the apparent fiber density (g / cm ³ ) by dividing the basis weight value by the thickness value and rounded off to the second decimal place.

(2) Fiber length 100 fibers were extracted from arbitrary three locations, and the length of the fiber was measured so as not to stretch. The number average of 300 measured fiber lengths was determined.

(3) Single fiber diameter The number average was calculated | required after observing 1000 times with a scanning electron microscope (JSM-5400LV, JEOL Co., Ltd.), selecting 100 fiber cross sections at random, and measuring a diameter. .

(4) Wear resistance (wear loss and pilling)
Measured according to JIS L 1096 (1999) 8.17.5 E method (Martindale method), furniture load (12 kPa), and C position. Here, the abrasion loss (mg) of the test cloth after the napped surface has been worn 20000 times is measured, and the appearance change (pilling occurrence or woven or knitted fabric exposure) is the largest up to 20000 times. The following judgment was made visually.

Grade 5: No change at all (good), Grade 4: Somewhat changed, Grade 3: Pilling (exposure) can be confirmed.
2nd grade: Pilling (exposure) is conspicuous 1st grade: Pilling (exposure) is very conspicuous (bad).

(5) Flame retardancy The following method A (result is Table 1) or method B (result is Table 2) was evaluated.

  A. It measured based on JIS D1201 (1998). The burning rate showed the maximum value (mm / min) of five measurements. In addition, "**" was displayed when the combustion length was less than 51 mm and the combustion time was less than 60 seconds.

  B. It measured based on UL-94 (thin material vertical combustion test). A test piece (20 x 5 cm) is wound in a cylindrical shape, attached vertically to a clamp, and subjected to a 3 second indirect flame with a 20 mm flame twice, and VTM-0, VTM-1, VTM-2, and Not are judged by the combustion behavior. Went.

(6) Entangled state of ultrafine fibers, presence / absence of pores in polymer elastic body With a scanning electron microscope (JSM-5400LV, manufactured by JEOL Ltd.), the cross section of the sheet was observed at 500 times to entangle fibers. The combined state was observed. 10 points are sampled at random, and within 200 μm in the thickness direction and within 200 μm in width, the ultrafine fiber bundle derived from the composite fiber cannot be clearly confirmed, or when the ultrafine fiber bundle is an average of 2 or less, the ultrafine fibers are mutually Entangled in Further, the presence of pores was confirmed by observing the portion where the polymer elastic body was present at 2000 times.

Example 1
Two S strands 2500 T / m and Z strands 2500 T / m of 84 decitex 72 filaments made of polyethylene terephthalate are arranged alternately, and one weft is arranged alternately on the weft to make a plain weave, 95 x 76 pieces / A woven fabric was produced with a weave density of 2.54 cm. Further, 43 parts of a copolyester containing 8 mol% of 5-sodium sulfoisophthalic acid as a sea component and 57 parts of polyethylene terephthalate as an island component, 4.3 decitex, 16 islands, average fiber The short island web having a basis weight of 260 g / m ² was produced by passing the sea-island type composite short fibers having a length of 5.1 cm through a card machine and a cross wrapper. This short fiber web is overlapped with a woven fabric on one side and subjected to needle punching at a driving density of 3000 pieces / cm ² using a 1 barb type needle punch machine, with a basis weight of 355 g / m ² , a thickness of 1.3 mm, and a fiber appearance. The density was 0.267 g / cm ³ . Next, this was immersed in hot water at 98 ° C. for 2 minutes to shrink, and then dried at 100 ° C. to remove moisture, thereby obtaining a composite fiber nonwoven fabric.

  The composite fiber nonwoven fabric was padded with an aqueous sodium hydroxide solution and then treated in a steam box at 105 ° C. for 5 minutes. Next, washing and drying were performed to obtain a nonwoven fabric in which ultrafine fibers and woven fabric were integrated. When the surface of this nonwoven fabric was observed with an electron microscope, it was extremely thinned into a fiber having a diameter of 3.7 μm (0.15 dtex).

  Next, the nonwoven fabric (A) in which the ultrafine fibers and the woven fabric are integrated on a net conveyor by a water jet punching machine having a nozzle head having a nozzle plate with a diameter of 0.12 mm and an interval of 0.6 mm. The front and back surfaces were treated three times at a pressure of 40 MPa. This was dried at 100 ° C. to remove moisture, and then buffed with sandpaper having a particle size of # 180 using a wide belt sander manufactured by Kikukawa Iron Works, Inc., and then dyed with a liquid dyeing machine. .

  Subsequently, an organic phosphorus flame retardant (SDF-PD manufactured by Daikyo Chemical Co., Ltd.) was padded and dried at 100 ° C.

  When the cross section of the leather-like sheet thus obtained was observed with an electron microscope, it was a structure in which ultrafine fibers were intertwined with each other. This sheet was excellent in wear resistance in spite of the absence of a polymer elastic body, and was extremely excellent in flame retardancy despite a small amount of flame retardant. Moreover, since there was little quantity of a flame retardant, there was almost no stickiness. The results obtained are summarized in Table 1.

(Example 2)
A leather-like sheet was obtained in the same manner as in Example 1 except that the amount of the organic phosphorus flame retardant applied was changed. Although the obtained results were excellent as shown in Table 1, the stickiness was slightly increased.

(Example 3)
In Example 2, a flame retardant was applied from the back by spraying, and hot air was blown from the back to dry the leather-like sheet. The flame retardancy was the same as in Example 2, but the stickiness was better than in Example 2.

Example 4
A leather-like sheet-like material was obtained in the same manner as in Example 1 except that the flame retardant was changed to a halogen flame retardant (Bigor No. 520PM, manufactured by Daikyo Chemical Co., Ltd.) and the amount was changed. As in Example 1, excellent flame retardancy was obtained.

(Example 5)
For the nonwoven fabric (A) obtained by integrating the ultrafine fibers and the woven fabric obtained in Example 1, a nozzle head having a nozzle plate with a diameter of 0.12 mm and an interval of 0.6 mm inserted on a net conveyor. In the water jet punch machine which has, the front and back were processed 3 times at a pressure of 17 MPa. This was dried at 100 ° C. to remove moisture, and then padded with an aqueous polyurethane emulsion (Evaphanol AP12 manufactured by Nikka Chemical Co., Ltd.) and then dried at 100 ° C. Furthermore, after using a wide belt sander manufactured by Kikukawa Iron Works Co., Ltd. and buffing with a sandpaper having a particle size of # 180, it was dyed with a liquid dyeing machine.

  Subsequently, an organic phosphorus flame retardant (SDF-PD manufactured by Daikyo Chemical Co., Ltd.) was padded and dried at 100 ° C.

When the cross section of the leather-like sheet-like material obtained here was observed with an electron microscope, it was a structure in which ultrafine fibers were entangled with each other, and the polyurethane was nonporous. Moreover, since the apparent density was as high as 0.426 g / cm ³ , the flame retardancy was excellent and the wear loss was small. The obtained results are shown in Table 1.

(Examples 6 to 8)
A leather-like sheet was obtained in the same manner as in Example 5 except that the flame retardant was changed. The obtained results are shown in Table 1.

Example 9
For the nonwoven fabric (A) obtained by integrating the ultrafine fibers and the woven fabric obtained in Example 1, a nozzle head having a nozzle plate with a diameter of 0.12 mm and an interval of 0.6 mm inserted on a net conveyor. In the water jet punch machine which has, the front and back were processed 3 times at a pressure of 14 MPa. This was dried at 100 ° C. to remove moisture, and then padded with an aqueous polyurethane emulsion (Evaphanol AP12 manufactured by Nikka Chemical Co., Ltd.) and then dried at 100 ° C. Furthermore, after using a wide belt sander manufactured by Kikukawa Iron Works Co., Ltd. and buffing with a sandpaper having a particle size of # 180, it was dyed with a liquid dyeing machine.

  Subsequently, an organic phosphorus flame retardant (SDF-PD manufactured by Daikyo Chemical Co., Ltd.) was padded and dried at 100 ° C.

When the cross section of the leather-like sheet-like material obtained here was observed with an electron microscope, it was confirmed that the polyurethane was non-porous although it was a trace amount that could hardly be confirmed. As described above, since the fiber entanglement is low and the amount of polyurethane is very small, the wear loss is small, but some pilling occurs. Moreover, since the apparent density was slightly low at 0.39 g / cm ³ , the flame retardancy was inferior to that of Example 1. The obtained results are shown in Table 1.

(Example 10)
A web was prepared through a card and a cross wrapper using a sea-island type composite short fiber having a single fiber fineness of 3 dtex, 36 islands, and a fiber length of 2.5 cm consisting of 45 parts by weight of polystyrene as a sea component and 55 parts by weight of polyethylene terephthalate as an island component. . Subsequently, it processed by 1500 bar / cm < ² > implantation density with the 1 barb type needle punch, and obtained the composite short fiber nonwoven fabric of the fiber apparent density 0.20g / cm < ³ >. Next, it is immersed in an aqueous solution of 12% by weight of polyvinyl alcohol (PVA) having a polymerization degree of 500 and a saponification degree of 88% heated to about 95 ° C. so as to have an adhesion amount of 25% by weight in terms of solid content with respect to the nonwoven fabric weight. Then, shrinkage treatment was performed for 2 minutes simultaneously with the impregnation with PVA, followed by drying at 100 ° C. to remove moisture. The obtained sheet was treated with trichrene at about 30 ° C. until the polystyrene was completely removed to obtain ultrafine fibers having a single fiber diameter of 0.19 μm. Next, after splitting into two pieces perpendicular to the thickness direction using a standard type splitting machine manufactured by Murota Manufacturing Co., Ltd., water having a nozzle diameter of 0.1 mm and a nozzle head with an interval of 0.6 mm is used. The front and back surfaces were treated with a jet punch at a processing speed of 1 m / min at 10 MPa and 20 MPa, and entangled with PVA removal. This was dried at 100 ° C. to remove moisture, and then buffed with sandpaper having a particle size of # 180 using a wide belt sander manufactured by Kikukawa Iron Works, Inc., and then dyed with a liquid dyeing machine. .

  Subsequently, an organic phosphorus flame retardant (SDF-PD manufactured by Daikyo Chemical Co., Ltd.) was padded and dried at 100 ° C.

  When the cross section of the leather-like sheet thus obtained was observed with an electron microscope, it was a structure in which ultrafine fibers were intertwined with each other. Moreover, despite the small amount of flame retardant, the flame retardancy was very excellent and there was almost no stickiness. On the other hand, the wear resistance was slightly inferior. The results obtained are summarized in Table 1.

(Comparative Example 1)
The same treatment as in Example 1 was conducted except that the flame retardant was not included. The obtained leather-like sheet was excellent in wear resistance but was insufficient in flame retardancy. The obtained results are shown in Table 1.

(Comparative Example 2)
The same treatment as in Example 2 was conducted except that no flame retardant was contained and polyurethane was applied. The obtained leather-like sheet was excellent in wear resistance but was insufficient in flame retardancy. The obtained results are shown in Table 1.

(Comparative Example 3)
After padding an aqueous polyurethane emulsion (Evaphanol AP12 manufactured by Nikka Chemical Co., Ltd.) without performing water jet punching on the non-woven fabric (A) obtained by integrating the ultrafine fibers and the woven fabric obtained in Example 1. And dried at 100 ° C.

  Furthermore, after using a wide belt sander manufactured by Kikukawa Iron Works Co., Ltd. and buffing with a sandpaper having a particle size of # 180, it was dyed with a liquid dyeing machine.

  When the cross section of the leather-like sheet thus obtained was observed with an electron microscope, it was a structure in which ultrafine fiber bundles were intertwined, and the polyurethane was nonporous. Further, since the amount of polyurethane was as large as 20% by mass, the flame retardancy was inferior to that of Comparative Example 2. The obtained results are shown in Table 1.

(Comparative Example 4)
A sea-island type composite short fiber having a single fiber fineness of 4.2 decitex, 16 islands, and a fiber length of 5.1 cm comprising 20 parts by weight of polystyrene as a sea component and 80 parts by weight of polyethylene terephthalate as an island component is passed through a card machine and a cross wrapper. A web was made. The obtained web was subjected to needle punching at a driving density of 2800 pieces / cm ² using a 1 barb type needle punching machine to obtain a composite short fiber nonwoven fabric having an apparent fiber density of 0.20 g / cm ³ . Next, it is immersed for 2 minutes in an aqueous solution of 5% by mass of PVA heated to 95 ° C. and having a polymerization degree of 500 and a saponification degree of 88%. At the same time as the impregnation, shrinkage treatment was performed. Thereafter, the nonwoven fabric was dried at 100 ° C. to remove moisture. Next, the composite short fiber nonwoven fabric is treated with trichlene at a liquid temperature of 30 ° C. until the polystyrene is completely removed, so that an ultrafine fiber having a single fiber diameter of 4.4 μm (0.21 dtex) is expressed from the composite short fiber. I let you.

  Next, it was impregnated with a DMF solution of polyether polyurethane and wet coagulated.

  This sheet was split in the thickness direction, and the ultrafine fiber nonwoven fabric side of the laminated sheet thus obtained was used with a wide belt sander manufactured by Kikukawa Iron Works, Ltd., and a silicon carbide abrasive sandpaper having a particle size of P320. Was brushed. Furthermore, it dye | stained with the disperse dye with the liquid flow dyeing machine.

  When the cross section of the leather-like sheet thus obtained was observed with an electron microscope, the ultrafine fiber bundle was intertwined with each other, and the polyurethane was porous. As shown in Table 1, the result of evaluating the flame retardancy of this sheet was slightly better than Comparative Example 3, but the flame retardancy was inferior.

(Comparative Example 5)
A paper sheet having a basis weight of 100 g / m ² and a back side of 30 g / m ² was prepared from polyester short fibers having a diameter of 3.2 μm and a fiber length of 0.5 cm obtained by direct spinning. Next, a 44 gauge, 77 g / m ² double circular knitting made of polyester fiber of 33 dtex 12 filaments is placed in the center, and a papermaking sheet is arranged on the front and back sides, and a nozzle plate having a diameter of 0.12 mm and an interval of 0.6 mm is provided. The front and back surfaces were treated three times at a pressure of 10 MPa with a water jet punch machine having an inserted nozzle head. This was dried at 100 ° C. to remove moisture, and then padded with an aqueous polyurethane emulsion (Evaphanol AP12 manufactured by Nikka Chemical Co., Ltd.) and then dried at 100 ° C. Furthermore, using a wide belt sander manufactured by Kikukawa Iron Works, Ltd., buffing was performed with sandpaper having a particle size of # 320, followed by dyeing with a liquid dyeing machine.

  Subsequently, an organic phosphorus flame retardant (SDF-PD manufactured by Daikyo Chemical Co., Ltd.) was padded and dried at 100 ° C.

The obtained leather-like sheet was short in fiber length, so there was a lot of wear loss, and the knitted fabric was partially exposed. Moreover, since the apparent density was somewhat low at 0.35 g / cm ³ , the flame retardancy was poor. The obtained results are shown in Table 1.

(Example 11)
A web was prepared through a card and a cross wrapper using sea island type composite short fibers having a single fiber fineness of 3 dtex, 36 islands, and a fiber length of 5.1 cm consisting of 45 parts by weight of polystyrene as a sea component and 55 parts by weight of polyethylene terephthalate as an island component. . Subsequently, it processed with the implantation density of 2500 pieces / cm < ² > with the 1 barb type needle punch, and obtained the composite short fiber nonwoven fabric of the fiber apparent density 0.21g / cm < ³ >. Next, it is immersed in an aqueous solution of 12% by weight of polyvinyl alcohol (PVA) having a polymerization degree of 500 and a saponification degree of 88% heated to about 95 ° C. so as to have an adhesion amount of 25% by weight on the basis of the nonwoven fabric weight. Then, shrinkage treatment was performed for 2 minutes simultaneously with the impregnation with PVA, followed by drying at 100 ° C. to remove moisture. The obtained sheet was treated with trichrene at about 30 ° C. until the polystyrene was completely removed to obtain ultrafine fibers having a single fiber diameter of 1.9 μm. Next, after splitting into two pieces perpendicular to the thickness direction using a standard type splitting machine manufactured by Murota Manufacturing Co., Ltd., water having a nozzle diameter of 0.1 mm and a nozzle head with an interval of 0.6 mm is used. The front and back surfaces were treated with a jet punch at a processing speed of 1 m / min at 10 MPa and 20 MPa, and entangled with PVA removal. This was dried at 100 ° C. to remove moisture, and then buffed with sandpaper having a particle size of # 320 using a wide belt sander manufactured by Kikukawa Iron Works, Inc., and then dyed with a liquid dyeing machine. .

An ethylene bispentabromobenzene (pentabromobenzene (non-decabro)) flame retardant was used as a flame retardant, and 65 g / m ² of solid content was knife coated on the back surface to obtain a leather-like sheet. When the cross section of the leather-like sheet thus obtained was observed with an electron microscope, it was a structure in which ultrafine fibers were intertwined with each other. This sheet was excellent in wear resistance in spite of the absence of a polymer elastic body, and was extremely excellent in flame retardancy despite a small amount of flame retardant. Moreover, it was excellent in napping quality compared with Example 1. The results obtained are summarized in Table 2.

(Example 12)
The same treatment as in Example 11 was performed except that the flame retardant was changed to phosphoric ester amide and applied by the padding method. Although the obtained leather-like sheet-like material showed excellent flame retardancy, it was harder than that obtained in Example 11 due to the large amount of flame retardant. The results obtained are summarized in Table 2.

(Comparative Example 6)
A web was prepared through a card and a cross wrapper using sea island type composite short fibers having a single fiber fineness of 3 dtex, 36 islands, and a fiber length of 5.1 cm consisting of 45 parts by weight of polystyrene as a sea component and 55 parts by weight of polyethylene terephthalate as an island component. . Subsequently, it processed with the implantation density of 2500 pieces / cm < ² > with the 1 barb type needle punch, and obtained the composite short fiber nonwoven fabric of the fiber apparent density 0.21g / cm < ³ >. Next, it is immersed in an aqueous solution of 12% by weight of polyvinyl alcohol (PVA) having a polymerization degree of 500 and a saponification degree of 88% heated to about 95 ° C. so as to have an adhesion amount of 25% by weight in terms of solid content with respect to the nonwoven fabric weight. Then, shrinkage treatment was performed for 2 minutes simultaneously with the impregnation with PVA, followed by drying at 100 ° C. to remove moisture. The obtained sheet was treated with trichrene at about 30 ° C. until the polystyrene was completely removed to obtain ultrafine fibers having a single fiber diameter of 1.9 μm. Next, it was impregnated with a DMF solution of polyether polyurethane and wet-coagulated.

  This sheet was split into two pieces perpendicular to the thickness direction using a standard type splitting machine manufactured by Murota Manufacturing Co., Ltd., and then a wide belt sander manufactured by Kikukawa Iron Works Co., Ltd. was used. After buffing with 320 sandpaper, it was dyed with a liquid dyeing machine.

An ethylene bispentabromobenzene (pentabromobenzene (non-decabro)) flame retardant was used as a flame retardant, and 65 g / m ² of solid content was knife coated on the back surface to obtain a leather-like sheet. When the cross section of the leather-like sheet thus obtained was observed with an electron microscope, the ultrafine fiber bundle was intertwined with each other, and the polyurethane was porous. As shown in Table 2, the results of evaluating the flame retardancy of this sheet were inferior in flame retardancy as compared with Example 1.

  The leather-like sheet-like material of the present invention is particularly suitably used in the field of upholstery materials for interior seats such as railways, automobiles, aircrafts, ships, and interior furniture, wall materials, sofas, chairs, etc. it can.

Claims (10)

  A leather comprising a nonwoven fabric in which ultrafine fibers having a fiber length of 2 cm or more are entangled with each other, the polymer elastic body is 15% by mass or less, and contains an organic phosphorus flame retardant or a halogen flame retardant Like sheet.   The leather-like sheet-like product according to claim 1, wherein the polymer elastic body is nonporous.   The leather-like sheet material according to claim 1 or 2, wherein the polymer elastic body is 1% by mass or less.   The leather-like sheet-like product according to claim 1, which is substantially made of a fiber material. The leather-like sheet material according to any one of claims 1 to 4, which has an apparent density of 0.40 to 0.70 g / cm ³ .   The leather-like sheet-like article according to any one of claims 1 to 5, comprising a woven or knitted fabric made of yarn having a twist number of 1300 to 3000 T / m.   The leather-like sheet material according to any one of claims 1 to 6, wherein the organic phosphorus flame retardant or the halogen flame retardant is selectively present on the back surface.   The exterior material of the electrical appliance which uses the leather-like sheet-like material in any one of Claims 1-7, and the flame retardance prescribed | regulated to UL94 is VTM-0. A method for producing the leather-like sheet according to any one of claims 1 to 8,
A step of forming a non-woven fabric by needle punching a very fine fiber-expressing fiber capable of expressing an ultra-fine fiber,
A step of expressing an ultrafine fiber from the ultrafine fiber expressing fiber,
The manufacturing method of the leather-like sheet-like material characterized by including the process of performing a high-speed fluid process on the nonwoven fabric which the said ultrafine fiber expressed by the pressure of 10-60 MPa in this order.   The method for producing a leather-like sheet-like material according to claim 9, wherein a flame retardant is applied to the back surface by coating.