JP2020105666A - Napped artificial leather and composite material - Google Patents

Abstract

To provide a napped artificial leather which is imparted with a high level of flame retardancy using a non-halogen flame retardant without impairing a sense of luxury on the surface, and a composite material using the same.SOLUTION: There is provided a napped artificial leather having a thickness of 0.25 to 1.5 mm comprising a fiber-entangled body including ultrafine fibers and an elastomer with which the fiber-entangled body is impregnated, in which the napped artificial leather includes phosphorus-based flame retardant particles adhered to the elastomer unevenly distributed in a range of 200 μm or less from a back surface and has a fabric weight of 100 to 300 g/m2. The phosphorus-based flame retardant particles have an average particle diameter of 0.1 to 30 μm, a phosphorus atom content of 14 mass% or more, a solubility in water at 30°C of 0.2 mass% or less, a melting point or a decomposition temperature (if a melting point is not present) of 150°C or more, and a phosphorus-based flame retardant particle content ratio of 1 to 6 mass% in terms of phosphorus atom.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a napped artificial leather having both a high level of flame retardancy and an excellent sense of surface quality, and a composite material using the same.

BACKGROUND ART Up to now, a napped artificial leather having an appearance like suede leather, which is obtained by raising one surface of an artificial leather raw machine obtained by impregnating a fiber entangled body such as a non-woven fabric of ultrafine fibers with a polymer elastic body, has been known. The napped artificial leather is used as a material for shoes, clothing, gloves, bags, balls and the like, and as an interior material for buildings and vehicles. The napped artificial leather is superior in quality stability, heat resistance, water resistance, and abrasion resistance to natural leather such as suede leather, and has advantages such as easy maintenance.

By the way, in recent years, an interior material using a leather-like sheet such as artificial leather has been adopted as an interior material for public transport such as aircrafts, ships and railway vehicles and an interior material for public buildings such as hotels and department stores. Interior materials used in public places are required to have a high level of flame retardancy such as self-extinguishing property, low smoke generation property and low heat generation property in order to ensure safety in case of fire. In order to satisfy such a requirement for flame retardancy, it has been widely practiced to mix a halogen-based flame retardant having high flame retardancy with an interior material. However, since halogen-based flame retardants generate toxic halogen gas when they burn, non-use of halogen-based flame retardants is recommended by environmental officials and users. For example, the following Patent Documents 1 to 3 disclose a technique of using a phosphorus-based flame retardant or a metal hydroxide-based flame retardant to make a leather-like sheet flame-retardant.

JP-A-56-050985 JP, 2009-235628, A JP, 2013-227685, A

A napped artificial leather obtained by impregnating a void inside a fiber entangled body of ultrafine fibers having a fineness of less than 1 dtex with a polymer elastic body and using a knitted or woven fabric of fibers of about 1 to 5 dtex, which is also called a regular fiber, as a base material. Compared to napped artificial leather, the surface touch is smoother and superior in quality. However, the napped artificial leather containing ultrafine fibers has a lower flame retardancy than the napped artificial leather containing regular fibers because the surface area of the fibers is larger. Further, it is difficult to impart a high level of flame retardancy to a napped artificial leather containing ultrafine fibers without using a halogen-based flame retardant. Examples of the halogen-free non-halogen flame retardant include phosphorus flame retardants. Specifically, for example, phosphorus-based flame retardants such as polyphosphoric acid metal salts, ammonium polyphosphate, polyphosphate inorganic salts such as carbamate polyphosphate, and phosphates such as guanidine phosphate are known. However, since these polyphosphate inorganic salts and phosphates have relatively high water solubility, the flame retardant swells or dissolves due to moisture, water, or heat in the use environment, and the drying treatment after applying the flame retardant. And bleed in. When the flame retardant swells, dissolves, or bleeds, the flame retardant may whiten or color the napped surface, which is the main surface, thereby impairing the high-quality surface of the napped artificial leather. In addition, aromatic phosphoric acid esters and aliphatic phosphoric acid esters such as aliphatic phosphonic acid esters and aliphatic cyclic phosphonic acid esters have relatively low water solubility, but their flame retardant effect is insufficient. There was, the texture of the napped artificial leather was impaired, and bleeding was likely to occur.

The present invention relates to a napped artificial leather containing a fiber entangled body of ultrafine fibers, and a napped artificial leather to which a high level of flame retardancy is imparted by using a non-halogen flame retardant without impairing the high-class surface feeling, and the same. The purpose is to provide a composite material.

One aspect of the present invention includes a fiber entangled body containing ultrafine fibers having a fineness of 0.5 dtex or less, and a polymer elastic body impregnated into the fiber entangled body, and a main surface that is a napped surface in which the ultrafine fibers are napped. A napped artificial leather having a thickness of 0.25 to 1.5 mm, further including phosphorus-based flame retardant particles attached to a polymeric elastic body unevenly distributed in a range of a thickness of 200 μm or less from a back surface with respect to a main surface, and a fabric weight Is 100 to 300 g/m ² , the phosphorus-based flame retardant particles have an average particle diameter of 0.1 to 30 μm, a phosphorus atom content of 14% by mass or more, and a solubility in water at 30° C. of 0.2% by mass or less, A napped artificial leather having a melting point or no melting point, a decomposition temperature of 150° C. or higher, and a phosphorous flame retardant particle content ratio of 1 to 6 mass% in terms of phosphorus atom conversion content. According to such a configuration, the phosphorus-based flame retardant particles as described above are unevenly distributed in a high concentration on the back surface side opposite to the main surface which is the design surface of the napped artificial leather, and the basis weight is 100 to 300 g/ by limiting the m ^2, in napped artificial leather comprising a fiber-entangled body of ultrafine fibers, without compromising the surface luxury, high levels of the napped artificial leather imparted with flame retardancy using a halogen-free flame retardant Obtainable.

Further, it is preferable that 90 to 100% by mass of the phosphorus-based flame retardant particles be present in a range of a thickness of 200 μm or less from the viewpoint of not impairing the high-class surface feeling.

Further, the content ratio of the phosphorus-based flame retardant particles in the total amount of the phosphorus-based flame retardant particles and the polymer elastic body is 5 to 20 mass% in terms of phosphorus atom, which means that the flame retardancy of the polymer elastic body is high. It is preferable because the decrease can be sufficiently suppressed.

The polymer elastic body includes a first polymer elastic body existing in the entire thickness section and a second polymer elastic body unevenly distributed in a thickness range of 200 μm or less. It is preferable that the phosphorus-based flame retardant particles are attached to the polymeric elastic body 2 in order to make the phosphorus-based flame retardant particles unevenly distributed in a thickness range of 200 μm or less.

Further, the content ratio of the phosphorus-based flame retardant particles in the total amount of the phosphorus-based flame retardant particles and the second polymeric elastic body is 10 to 30% by mass in terms of phosphorus atom, that is, the second polymeric elasticity. It is preferable because the effect of reducing the flame retardancy by the body is small.

As the phosphorus-based flame retardant particles described above, organic phosphinic acid metal salts, aromatic phosphonic acid esters, and phosphoric acid ester amides are particularly preferable.

Further, another aspect of the present invention is a composite material in which an interior base material is adhered to the back surface of any one of the napped artificial leathers described above with an adhesive. Such a composite material has both a high level of flame retardancy and an excellent surface quality as an interior material or exterior material whose surface is decorated with napped artificial leather.

For example, the above-mentioned composite material has a total heat generation amount (THR) of 10 MJ/m ² or less, a maximum heat generation amount (PHRR) of 250 kW/m ² or less, or a maximum average rate of heat dissipation (MARHE) of 90 kW/m ² The following can be realized.

According to the present invention, in a napped artificial leather containing a fiber entangled body of ultrafine fibers, a napped artificial leather provided with a high level of flame retardancy by using a non-halogen flame retardant can be obtained without impairing the high-grade feeling of the surface. ..

The napped artificial leather of the present embodiment includes a fiber entangled body containing ultrafine fibers having a fineness of 0.5 dtex or less, and a polymer elastic body impregnated in the fiber entangled body, and is a napped surface in which the ultrafine fibers are napped. A napped artificial leather having a main surface and a thickness of 0.25 to 1.5 mm, further including phosphorus-based flame retardant particles attached to a polymeric elastic body unevenly distributed in a range of a thickness of 200 μm or less from the back surface with respect to the main surface. , The basis weight is 100 to 300 g/m ² , the phosphorus-based flame retardant particles have an average particle diameter of 0.1 to 30 μm, a phosphorus atom content of 14% by mass or more, and a solubility in water at 30° C. of 0.2% by mass. Hereinafter, the napped artificial leather has a melting point or a melting point of 150° C. or more when there is no melting point, and the phosphorus-based flame retardant particle content ratio is 1 to 6 mass% in terms of phosphorus atom conversion content ratio.

The napped artificial leather of the present embodiment includes, for example, a first polymer elastic body impregnated with a fiber entangled body containing ultrafine fibers having a fineness of 0.5 dtex or less, and is a napped surface with napped ultrafine fibers. 200 μm or less from the back surface of a resin liquid containing phosphorus-based flame retardant particles and a second polymer elastic body on the back surface of the napped artificial leather having a thickness of 0.25 to 1.5 mm with respect to the main surface of the raw machine. It is obtained by performing a flame retardant treatment so that it is unevenly distributed in the range of.

Examples of the fiber entangled body containing ultrafine fibers having a fineness of 0.5 dtex or less include fiber structures such as nonwoven fabrics, woven fabrics and knitted fabrics containing ultrafine fibers having a fineness of 0.5 dtex or less. Among these, a non-woven fabric of ultrafine fibers is particularly preferable because it provides a napped artificial leather excellent in suppleness and fullness because of its high homogeneity. In the present embodiment, as a fiber entangled body of ultrafine fibers, a nonwoven fabric of ultrafine fibers will be described in detail as a representative example.

As a method for producing a nonwoven fabric of ultrafine fibers, for example, a web is produced by melt-spinning sea-island type composite fibers, the web is entangled, and then the sea component is selectively removed from the sea-island type composite fibers to obtain ultrafine fibers. And a method of forming. As a method for producing a web, a method of forming a long fiber web by collecting on a net without cutting sea-island type composite fibers of long fibers spun by a spunbond method, or cutting the long fibers into staples. And a method of forming a short fiber web. Of these, long-fiber webs are particularly preferable because they are excellent in compactness and fullness. Further, the formed web may be subjected to a fusion treatment in order to impart morphological stability. Examples of the entanglement treatment include a method of stacking about 5 to 100 webs, and needle punching or high-pressure water flow treatment. In addition, in any of the steps from removing the sea component of the sea-island type composite fiber to forming the ultrafine fiber, the sea-island type composite fiber is densified and enriched by performing a fiber shrinkage treatment such as heat shrinkage treatment with steam. The feeling can be improved.

In the present embodiment, the case of using the sea-island type composite fiber will be described in detail. However, even if an ultrafine fiber generating fiber other than the sea-island type composite fiber is used, the ultrafine fiber generating type fiber is not used, and the ultrafine fiber is directly used. May be spun into a nonwoven fabric. In addition, as a specific example of the ultrafine fiber-generating fiber other than the sea-island type composite fiber, a plurality of ultrafine fibers are lightly bonded and formed immediately after spinning, and a plurality of ultrafine fibers are formed by loosening by mechanical operation. Any fiber capable of forming an ultrafine fiber, such as a peelable split-type fiber or a petal-type fiber obtained by alternately collecting a plurality of resins in a petal-like shape in the melt spinning process, is not particularly limited. ..

The resin of the island component forming the ultrafine fibers forming the sea-island type composite fiber is not particularly limited. Specifically, for example, aromatic polyesters such as polyethylene terephthalate (PET), isophthalic acid modified PET, sulfoisophthalic acid modified PET, polybutylene terephthalate, polyhexamethylene terephthalate; polylactic acid, polyethylene succinate, polybutylene succinate, Aliphatic polyesters such as polybutylene succinate adipate and polyhydroxybutyrate-polyhydroxyvalerate resin; polyamides such as polyamide 6, polyamide 66, polyamide 10, polyamide 11, polyamide 12, polyamide 6-12; polypropylene, polyethylene, polybutene Polyolefin such as polymethylpentene and chlorine-based polyolefin. These may be used alone or in combination of two or more. Among these, PET or modified PET, polylactic acid, polyamide 6, polyamide 12, polyamide 6-12, polypropylene and the like are preferable.

Further, as the resin of the sea component forming the sea-island type composite fiber, a resin having a different solubility to a solvent or a decomposability to a decomposing agent than the resin of the island component is selected. Specific examples of the resin that constitutes the sea component include water-soluble polyvinyl alcohol resins, polyethylene, polypropylene, polystyrene, ethylene propylene resin, ethylene vinyl acetate resin, styrene ethylene resin, and styrene acrylic resin.

The sea component of the sea-island type composite fiber is dissolved or decomposed and removed at an appropriate stage after forming the web. The sea-island type composite fibers are made into ultrafine fibers by such decomposition removal or dissolution extraction removal, and ultrafine fibers in the form of fiber bundles are formed.

The fineness of the ultrafine fibers is 0.5 dtex or less. Further, it is preferably 0.001 to 0.5 dtex, and particularly preferably 0.01 to 0.3 dtex. When the fineness is more than 0.5 dtex, the napped surface tends to have a high-grade feeling. The fineness is determined by taking a cross section in the thickness direction of the napped artificial leather with a scanning microscope at a magnification of 2000 times to obtain the cross-sectional area of the single fiber, and from the cross-sectional area and the specific gravity of the resin forming the fiber, one single fiber is obtained. The fineness of can be calculated. The fineness can be defined as the average value of the average fineness of 100 single fibers, which is obtained from the photographed image.

The first elastic polymer is evenly applied to the entire nonwoven fabric. The first polymer elastic body imparts morphological stability to a fiber entangled body containing ultrafine fibers having a fineness of 0.5 dtex or less, or imparts a high-grade feeling to the napped surface by restraining the ultrafine fibers. Examples of the first polymer elastic body include polyurethane, acrylonitrile elastomer, olefin elastomer, polyester elastomer, polyamide elastomer, and acrylic elastomer. These may be used alone or in combination of two or more. Of these, polyurethane is preferred.

The first polymer elastic body is, for example, a fiber entanglement of ultrafine fiber-generating fibers such as sea-island type composite fibers for forming ultrafine fibers, or a fiber entanglement of ultrafine fibers and a polymer such as polyurethane emulsion. After impregnated with an elastic emulsion or polyurethane solution, it is applied to the fiber entangled body by solidifying. Examples of the method for impregnating the fiber entangled body with the emulsion or solution of the first polymer elastic body include a method using a knife coater, a bar coater, or a roll coater, and a method of dipping. When an emulsion is used, a method of heat treatment in a drying device at 50 to 200° C., a method of heat treatment in a dryer after infrared heating, a method of heat treatment in a dryer after steam treatment, or ultrasonic wave The polymer elastic body can be solidified by a method of performing heat treatment with a dryer after heating, or a method of combining these.

When the fiber entangled body is impregnated with the polymer elastic emulsion and then dried, the emulsion may migrate to the surface layer of the fiber entangled body, which may make it difficult to uniformly apply the emulsion in the thickness direction. In such a case, the dispersed particle size of the emulsion is adjusted, the type and amount of the ionic groups of the elastic polymer are adjusted, and an ammonium salt whose pH changes depending on the temperature of about 40 to 100°C is added. To reduce the stability of water dispersion, or to associate heat-sensitive gelation of monovalent or divalent alkali metal salt or alkaline earth metal salt, nonionic emulsifier, associative water-soluble thickener, water-soluble silicone compound, etc. The migration can be suppressed by adding an agent or a water-soluble polyurethane compound to lower the water dispersion stability.

The first polymer elastic body preferably has a 100% modulus of 0.5 to 7 MPa, more preferably 1 to 5 MPa from the viewpoint that a supple texture can be obtained and a smooth surface touch and surface physical properties can be imparted. .. If the 100% modulus is too low, it tends to soften when heat is applied and restrain the ultrafine fibers, resulting in a decrease in supple texture and smooth surface touch. If the 100% modulus is too high, smooth surface touch tends to be deteriorated and the texture tends to be hard.

The ratio of the first polymeric elastic body contained in the napped artificial leather is 3 to 35% by mass, further 5 to 25% by mass, and particularly 7 to 20% by mass, which indicates high flame retardancy and high surface quality. It is preferable from the viewpoint of excellent balance with feeling, morphological stability and surface physical properties.

The fiber entangled body containing the first polymer elastic body is subjected to a wet heat shrinkage treatment or a press treatment as necessary to adjust the apparent density, the basis weight and the thickness to make a synthetic leather raw material. To be Then, the raw fabric of the artificial leather is sliced if necessary. Then, by buffing at least one surface of the artificial leather raw material with a contact buff, an emery buff or the like, a raised artificial leather raw material having a raised surface is manufactured. The buffing is preferably performed using, for example, sandpaper or emery paper having a count of 120 to 600. In this way, a raw fabric of napped artificial leather having a napped surface in which fibers on the buffed surface are napped and napped with ultrafine fibers is manufactured. If necessary, the napped artificial leather machine can be dyed, kneaded and softened, blanked and softened, reverse-seal brushing, antifouling, hydrophilic, lubricant, softener, and antioxidant. Finishing treatment such as agent treatment, ultraviolet absorber treatment, and fluorescent agent treatment may be performed.

The thickness of the raised nap artificial leather is approximately equal to the thickness of the finally obtained nap artificial leather. The thickness of the raised nap artificial leather is specifically 0.25 to 1.5 mm, preferably 0.3 to 1.0 mm. When the thickness of the raised nap artificial leather exceeds 1.5 mm, it becomes difficult to obtain a sufficient flame retardant effect.

The napped artificial leather of the present embodiment has phosphorus-based flame retardant particles and a second polymer elastic body on the back surface of the nap artificial surface having a thickness of 0.25 to 1.5 mm, which is opposite to the napped surface of the main surface of the machine. It is obtained by subjecting the resin liquid containing and to a flame retarding treatment which is a treatment for unevenly distributing the resin liquid in the range of 200 μm or less from the back surface. Here, in the napped artificial leather of the present embodiment, the phosphorus-based flame retardant particles are unevenly distributed in the range of a thickness of 200 μm or less from the back surface with respect to the main surface, most of the phosphorus-based flame retardant particles present in the napped artificial leather, specifically Specifically, it means that 90 to 100% by mass, and further 95 to 100% by mass of the phosphorus-based flame retardant particles are present in a range of a thickness of 200 μm or less from the back surface with respect to the main surface. The thickness of the phosphor-based flame retardant particles from the back surface with respect to the unevenly distributed main surface is preferably 50 to 200 μm, and more preferably 70 to 180 μm. The thickness of the region in which the phosphorus-based flame retardant particles are unevenly distributed in the napped artificial leather is confirmed by observing a cross section in a direction parallel to the thickness direction of the napped artificial leather with a scanning electron microscope.

In this way, the phosphorus content of the phosphorus flame retardant particles in the range of 200 μm or less from the back surface of the main surface of the napped artificial leather to the napped surface is 1 to 6% by mass in terms of phosphorus atom conversion content. By unevenly distributing the particles of the flame-retardant agent, it is possible to impart a high level of flame-retardancy by using the non-halogen flame-retardant agent without impairing the high-grade feeling of the surface.

The content of the phosphorus-based flame retardant particles unevenly distributed in the range of 200 μm or less from the back surface to the napped surface of the main surface in the napped artificial leather is 1 to 6 mass% in terms of phosphorus atom, and preferably 2.5. Is about 5% by mass. When the phosphorus atom-based content of the phosphorus flame retardant particles in the napped artificial leather is less than 1% by mass, a high level of flame retardancy cannot be obtained. Further, when the content ratio of phosphorus-based flame retardant particles in the napped artificial leather in terms of phosphorus atom exceeds 6% by mass, the phosphorus-based flame retardant particles are fixed from the back surface to a thickness of 200 μm or less without falling off. It becomes difficult to disperse the napped artificial leather, and the suppleness of the napped artificial leather is lost, and the high-grade feeling of the surface is deteriorated.

Moreover, the phosphorus-based flame retardant particles contained in the napped artificial leather of the present embodiment have an average particle diameter of 0.1 to 30 μm, a phosphorus atom content ratio of 14% by mass or more, and a solubility in water at 30° C. of 0.2% by mass. Hereinafter, it is a flame-retardant compound containing a phosphorus atom which is a particulate solid at room temperature and has a decomposition temperature of 150° C. or higher when a melting point or no melting point is present.

The phosphorus-based flame retardant particles have an average particle size of 0.1 to 30 μm, preferably 1 to 10 μm. When the average particle diameter exceeds 30 μm, the content of the phosphorus-based flame retardant particles is sufficiently within the range of 200 μm or less from the back surface of the napped artificial leather so that the content of the phosphorus-based flame retardant particles is 1 to 6% by mass in terms of phosphorus atom conversion. It becomes difficult to infiltrate into, and the flame retardant effect tends to be insufficient. When the average particle size is less than 0.1 μm, the particles are likely to be aggregated and unevenly dispersed, so that unevenness in flame retardance is likely to occur.

The phosphorus atom content of the phosphorus-based flame retardant particles is 14% by mass or more, preferably 15% by mass or more, and more preferably 20% by mass or more. When the phosphorus atom content ratio of the phosphorus-based flame retardant particles is less than 14% by mass, it becomes difficult to impart a high level of flame retardancy.

Further, the phosphorus-based flame retardant particles have a solubility in water at 30° C. of 0.2% by mass or less, and preferably 0.15% by mass or less. When phosphorus-based flame retardant particles having a solubility in water at 30° C. of more than 0.2% by mass are used, they tend to bleed to the napped surface when they absorb moisture during production or during use or get wet with water. ..

Further, as the phosphorus-based flame retardant particles, the solubility in hot water at 90° C. of hot water is 5% by mass or less, and further 3% by mass or less, even when they come into contact with hot water during production or use, It is preferable in that it is difficult to bleed the napped surface or to change in dimension.

Further, the phosphorus-based flame retardant particles are solid particles at room temperature which have a melting point or a decomposition temperature of 150° C. or more, preferably 200° C. or more when no melting point is present. When the melting point or the melting point does not exist and the decomposition temperature is lower than 150° C., the flame retardant is softened by drying after being treated, etc. to be solidified and not in the form of particles, and the ultrafine fibers are bundled, It is easy to damage the surface touch and texture. In addition, it becomes easy to melt and drop in the combustion process, and it becomes difficult to impart a high level of flame retardancy. Here, the melting point of the phosphorus-based flame retardant particles is specified by the melting peak temperature of thermogravimetric differential thermal analysis (TG-DTA) and differential scanning calorimeter analysis (DSC). Further, the thermal decomposition temperature when there is no melting point is specified by the decomposition start temperature by thermogravimetric differential thermal analysis (TG-DTA). The measurement conditions are not particularly limited, but the measurement is performed at a temperature rising rate of 5 to 10° C./min in a nitrogen atmosphere.

The phosphorus-based flame retardant particles as described above are selected from organic phosphinic acid metal salts such as metal salts of dialkylphosphinic acid and metal salts of monoalkylphosphinic acid; aromatic phosphonic acid esters; phosphoric acid ester amides and the like. These may be used alone or in combination of two or more. Among these, a metal salt of dialkylphosphinic acid or a metal salt of monoalkylphosphinic acid is preferable because it has high water resistance and heat resistance, a high phosphorus atom content, and a high flame retardant effect.

The second polymeric elastic body used for fixing the phosphorus-based flame retardant particles contained in the napped artificial leather of the present embodiment may be the same as or different from the first polymeric elastic body described above. It may be. Of these, polyurethane is preferable because it has an excellent balance of physical properties. Further, it is preferable that the second polymer elastic body has a 100% modulus of 0.5 to 5 MPa, further 1 to 4 MPa, since a supple texture can be obtained and the flame retardant can be prevented from falling off.

The resin liquid containing phosphorus-based flame retardant particles and the second polymeric elastic body is thickened from the back surface to the back surface of the nap artificial surface of the nap artificial artificial leather having a thickness of 0.25 to 1.5 mm described above with respect to the nap surface. There is no particular limitation on the method of flame-retardant treatment that is applied so as to be unevenly distributed in the range of 200 μm or less. Specifically, the phosphorus-based flame retardant particles and the second polymer elastic body are applied to the back surface of the main surface of the napped artificial leather with respect to the napped surface by, for example, gravure coating, direct coating, roll coating, or spray coating. A method of applying the treatment liquid containing the composition while adjusting the coating amount and the viscosity and then drying it can be mentioned.

The viscosity of the treatment liquid containing the phosphorus-based flame retardant particles and the second polymer elastic body is 200 to 10000 mPa·sec, and further 500 to 5000 mPa·sec. The polymer elastic body and the napped artificial leather are appropriately sunk from the back side of the greige machine, and are easily unevenly distributed within a thickness of 200 μm or less, which does not impair the napped surface, which is the main surface, and is highly difficult. It is preferable from the viewpoint of imparting flammability.

The resin liquid containing the second elastic polymer contains, for example, phosphorus flame retardant particles prepared by dispersing phosphorus flame retardant particles in an emulsion of polyurethane, which is an emulsion of the second elastic polymer. A polyurethane emulsion is preferably used. In the case of a polyurethane emulsion, the average particle size of the emulsion is preferably 10 μm or less, and more preferably 5 μm. The drying temperature of the resin liquid is not particularly limited, but it is usually preferably 100 to 160°C.

The content ratio of the phosphorus-based flame retardant particles in the total amount of the phosphorus-based flame retardant particles and the second polymer elastic body is 10 to 30% by mass, and further 12 to 25% by mass in terms of phosphorus atom. preferable. When the content ratio of the phosphorus-based flame retardant particles in the total amount of the phosphorus-based flame retardant particles and the second polymeric elastic body is the above-mentioned ratio, the influence of the flame retardancy decrease due to the combustion of the second polymeric elastic body Is preferable because it is small.

Further, the content ratio of the phosphorus-based flame retardant particles in the total amount of the phosphorus-based flame retardant particles and the second polymer elastic body is in the range of 10 to 30 mass% in terms of phosphorus atom, and The mass of the fuel particles is preferably 60 to 90% by mass, more preferably 70 to 85% by mass.

The proportion of the second polymeric elastic body contained in the napped artificial leather is not particularly limited, but it is 2 to 15% by mass, more preferably 4 to 10% by mass. It is preferable because the phosphorus-based flame retardant particles can be sufficiently fixed while the decrease in flame retardancy due to the above is suppressed.

When the ultrafine fibers form a fiber bundle derived from the sea-island type composite fiber, the polymer elastic body may be impregnated inside the fiber bundle or attached to the outside of the fiber bundle. When the sea-island type composite fiber is subjected to the ultrafine fiber treatment, the thermoplastic resin of the sea component is removed from the sea-island type composite fiber to form voids inside the ultrafine fiber bundle. Therefore, the second polymeric elastic body applied after the sea-island type composite fiber is subjected to the ultrafine fiber treatment is likely to bind the ultrafine fibers that form the fiber bundle by impregnating the inside of the fiber bundle. Therefore, the second polymer elastic body impregnated in the ultrafine fiber bundle contributes to restrain the ultrafine fiber bundle and improve the shape retention of the fiber entangled body.

The ratio of the total amount of the polymer elastic body including the first polymer elastic body and the second polymer elastic body contained in the napped artificial leather is not particularly limited, but is 2 to 40% by mass, and further 5 The content of ˜35% by mass is preferable because the influence of the decrease in flame retardancy due to the combustion of the polymeric elastic body can be reduced.

Further, the content ratio of the phosphorus-based flame retardant particles in the total amount of the phosphorus-based flame retardant particles and the polymer elasticity including the first polymer elasticity and the second polymer elasticity is 5 to 20% by mass in terms of phosphorus atom. Is preferable, and more preferably 6 to 20 mass% from the viewpoint of excellent balance between flame retardancy and suppleness of napped artificial leather.

The napped artificial leather may be softened for the purpose of smoothing the surface touch while improving the smoothness of the surface. Examples of the softening include a method in which napped artificial leather is brought into close contact with an elastic sheet, mechanically contracted in the vertical direction (MD in the production line), and heat-treated by heat treatment in the contracted state.

The napped artificial leather of the present embodiment thus obtained has a basis weight of 100 to 300 g/m ² , preferably 150 to 300 g/m ² , and more preferably 170 to 250 g/m ² . When the fabric weight of the napped artificial leather is less than 100 g/m ² , the phosphorus-based flame retardant particles tend to affect the napped surface and lower the high-grade feeling of the surface. In addition, when the fabric weight of the napped artificial leather exceeds 300 g/m ² , the effect of imparting flame retardancy to the napped side decreases.

The napped artificial leather has a thickness of 0.25 to 1.5 mm, preferably 0.3 to 1.0 mm. When the thickness of the napped artificial leather is less than 0.25 mm, the flame retardant is likely to be exposed on the surface and the surface quality and touch are deteriorated. When the thickness of the napped artificial leather exceeds 1.5 mm, the flame retardancy is lowered.

The apparent density of the napped artificial leather is not particularly limited, but it is 0.25 to 0.75 g/cm ³ , and more preferably 0.35 to 0.65 g/cm ³ for the feeling of nap and surface touch. It is favorable, and is preferable because it has an excellent balance between a fullness and a supple texture.

The napped artificial leather of the present embodiment is preferably used, for example, as a wall covering material in which a napped artificial leather and an interior base material (back board) are bonded together with an adhesive for composites. Specific examples of the interior base material include concrete, brick, tile, ceramic tile, fiber reinforced cement plate, glass fiber mixed cement plate, calcium silicate plate, steel, aluminum, metal plate, glass, mortar, plaster, Examples include stone, gypsum board, rock wool, glass wool board, wood wool cement board, hard wood wool cement board, wood wool cement board, pulp cement board, and flame-retardant plywood. Among them, concrete, brick, roof tile, ceramic tile, fiber reinforced cement board, glass fiber mixed cement board, calcium silicate board, steel, aluminum, in order to suppress combustibility when combined with napped artificial leather, Metal plates and glass are preferred.

Examples of adhesives for composites include starch-based, (alkyl)cellulose-based, vinyl acetate-based, ethylene vinyl acetate-based, acrylic resin-based, polyurethane-based, chloroprene-based, phenol-based, nitrile-based, ester-based, silicone Examples thereof include adhesives containing a mixture of a system, a fluorine system, a copolymer or a mixture thereof, or a metal compound such as a metal salt or a hydroxide. Among these, starch-based, (alkyl)cellulose-based, vinyl acetate-based, chloroprene-based, phenol-based, nitrile-based, fluorine-based, silicone-based, and these, from the viewpoint of suppressing combustibility when combined with napped artificial leather Examples thereof include copolymers and mixtures, and adhesives mixed with metal salts and hydroxides.

The flame retardancy of a composite material obtained by bonding an interior base material to the back surface of a napped artificial leather with an adhesive can be evaluated using a cone calorimeter. The flame-retardant properties evaluated by the combustion test using a cone calorimeter include the total heat generation amount by combustion (THR; MJ/m ² ), the maximum heat generation amount by combustion per unit area and unit time (PHRR; kW/ m ² ), the maximum average rate of heat dissipation (MARHE; kW/m ² ).

Composite material on the back surface of the napped artificial leather of the present embodiment formed by bonding the interior base material with an adhesive, the total calorific value (THR) is 10 MJ / m ² or less, further realizing the 8 MJ / m ² or less of the composite material It is possible. Further, the composite material of the present embodiment can realize a composite material having a maximum heat generation amount (PHRR) of 250 kW/m ² or less, and further 200 kW/m ² or less. Further, the composite material of the present embodiment can realize a composite material having a maximum average heat dissipation rate (MARHE; kW/m ² ) of 90 kW/m ² or less.

Further, the napped artificial leather of the present embodiment has a high level of flame retardancy, a high-class surface feeling, a supple texture, and a sense of fulfillment, and therefore, for example, a public transportation machine such as an aircraft, a ship, a railroad, a vehicle, or It is preferably used for applications requiring a high level of flame retardancy such as self-extinguishing property, low heat generation property, low smoke generation property, such as seats of public buildings such as hotels and department stores, materials for sofas, interiors such as walls, and the like.

Hereinafter, the present invention will be described more specifically with reference to Examples. The scope of the present invention is not limited to the examples.

[Example 1]
<Manufacture of napped artificial leather raw machine>
The sea-island composite fiber was melt-spun using water-soluble thermoplastic polyvinyl alcohol (PVA) as the sea component resin and isophthalic acid-modified polyethylene terephthalate as the island component resin. Specifically, the molten resin of the sea component resin and the island component resin is respectively supplied to the spinneret for composite spinning in which nozzle holes for forming 25 island component resin distributions in the sea component resin are arranged. The molten fiber of the sea-island type composite fiber was discharged from the nozzle hole. At this time, the pressure was adjusted so that the mass ratio of the sea component and the island component was 25/75, ie, sea component/island component.

Then, the sea-island composite fiber having a fineness of 3.3 dtex was spun by drawing the molten fiber of the sea-island composite fiber with a suction device and stretching. The spun sea-island type composite fiber was continuously deposited on a movable net, and was lightly pressed by a heated metal roll to suppress surface fluffing. Then, after separating the sea-island type composite fiber from the net, the web was passed between a metal roll and a back roll and hot-pressed to obtain a web having a basis weight of 31 g/m ² .

Next, using a cross-wrapper device, eight layers of web were piled up so that the total basis weight was 250 g/m ² , and needle-punching was alternately performed from both sides of the web for entanglement treatment. The basis weight of the entangled web, which was the web after needle punching, was 350 g/m ² .

The entangled web was subjected to wet heat shrinkage for 30 seconds under the conditions of 70° C. and 50% RH humidity. The area shrinkage ratio before and after the wet heat shrinkage treatment was 47%.

Then, the contracted entangled web was impregnated with an emulsion of a first polyurethane (first elastic polymer) containing ammonium sulfate as a gelling agent, and then dried. The first polyurethane was a self-emulsifying amorphous polycarbonate urethane containing 4,4'-dicyclohexylmethane diisocyanate as a diisocyanate component and having a 100% modulus of 3.0 MPa.

Then, the entangled web provided with the first polyurethane is immersed in hot water to dissolve and remove the PVA to obtain a non-woven fabric in which a fiber bundle containing 25 ultrafine fibers with a fineness of 0.1 dtex is three-dimensionally entangled. A raw machine of artificial leather containing was produced. The content of the first polyurethane in the artificial leather greige was 12% by mass.

Then, the raw fabric of the artificial leather was sliced and divided into two in the thickness direction, and the anti-slicing surface was buffed to finish the raw fabric of the napped artificial leather having a suede-like napped face. The napped artificial leather had a thickness of 0.35 mm, a basis weight of 175 g/m ² , and an apparent density of 0.50 g/cm ³ .

Then, the napped artificial leather greige was dyed using a circular dyeing machine, dried, then impregnated with a softening agent, and further dried.

Then, using a gravure coater equipped with a 35-mesh gravure roll on the sliced surface of the dyed napped artificial leather raw machine, particles of a metal salt of dialkylphosphinic acid, which is a phosphorus-based flame retardant, were dispersed at 2000 mPa·sec. The second polyurethane emulsion was applied at 110 g/m ² and dried at 120° C. to remove water. The particles of the metal salt of dialkylphosphinic acid have a dispersed particle diameter (median diameter: D ₅₀ ) of 4 μm measured by a laser diffraction/scattering particle diameter distribution measuring device and a phosphorus atom content rate of 23.5% by mass. The solubility in water at 30°C was less than 0.2% by mass, and the melting point and decomposition temperature were more than 250°C.

Further, the second polyurethane emulsion contained 10% by mass of the second polyurethane (second elastic polymer) and 28% by mass of the metal salt of dialkylphosphinic acid. The second polyurethane was a forced emulsification type amorphous polycarbonate urethane containing 4,4'-dicyclohexylmethane diisocyanate as a diisocyanate component and having a 100% modulus of 1.0 MPa.

Then, the flame-retardant napped artificial leather raw material is shrunk at a drum temperature of 120° C. and a conveying speed of 10 m/min to shrink 5.0% in the vertical direction (length direction), and then the surface is sealed. By carrying out, napped artificial leather having a suede-like napped surface was obtained. The napped artificial leather had a thickness of 0.4 mm, a basis weight of 225 g/m ² , and an apparent density of 0.56 g/cm ³ .

The napped artificial leather contained 10% by mass of the first polyurethane, 5% by mass of the second polyurethane, and 14.4% by mass of particles of the metal salt of dialkylphosphinic acid. As a result, the napped artificial leather contained 3.4 mass% of a metal salt of dialkylphosphinic acid in terms of phosphorus atom conversion content. In addition, the phosphorus atom-equivalent mass% relative to the total amount of the particles of the metal salt of dialkylphosphinic acid, the first polyurethane and the second polyurethane was 11.5 mass %. Further, the phosphorus atom-equivalent mass% based on the total amount of the second polyurethane and the particles of the metal salt of dialkylphosphinic acid was 17.4 mass %.

Then, the obtained napped artificial leather was evaluated according to the following evaluation methods.

(Surface appearance)
The napped surface of the napped artificial leather was touched and judged according to the following criteria.
A: The surface touch was smooth, and there was no rough feel due to the phosphorus-based flame retardant particles.
B: The surface touch was rough, and the quality was inferior.
C: The texture was hard and inferior in luxury.
D: Phosphorus flame retardant particles bleed during storage, the surface is whitened, and slime is felt.

(Thickness, basis weight and apparent density)
According to JIS L1913, the apparent density (g/cm ³ ) is calculated by measuring the thickness (mm) and the basis weight (g/cm ² ) of the napped artificial leather and dividing the basis weight by the thickness for conversion. did.

(Measurement of thickness of unevenly distributed region of phosphorus-based flame retardant particles attached to polymer elastic body)
The cross section direction of the napped artificial leather was cut out, and 10 points were uniformly selected from the whole cross section, and the thickness of the region where the phosphorus-based flame retardant particles were present was measured from the back surface at 10 points with a scanning electron microscope at a magnification of 100 times. Then, the average value of 8 points excluding the maximum value and the minimum value of the thickness was taken as the unevenly distributed thickness of the phosphorus-based flame retardant particles.

(Average particle size of phosphorus flame retardant particles)
Cut out the cross section direction of the napped artificial leather, select 10 points evenly from the entire cross section, select the area where the phosphorus flame retardant particles are present from the back side with a scanning electron microscope at a magnification of 1000 times, and select the diameter of 10 particles. The average value of the eight particle sizes measured and excluding the maximum and minimum values was defined as the average particle size of the phosphorus-based flame retardant particles.

(Vertical method combustion test: self-extinguishing)
The vertical method flame resistance of the napped artificial leather was measured by the FAR25 Appendix F Part1(a)(1)(ii) US aircraft interior material combustion test standard. Specifically, the napped artificial leather was cut into 50.8 mm×304.8 mm to prepare a test piece. Then, the test piece was vertically fixed to the sample holder of the combustion test apparatus. A burner was placed directly below one end of the test piece, and after indirect flame for 12 seconds, the burning distance, self-extinguishing time, and drop self-extinguishing time of the test piece were measured. The average of n=10 was calculated.

<Evaluation of composite material that is a composite of napped artificial leather>
The composite material obtained by making the obtained napped artificial leather into a composite by the following method was evaluated according to the following evaluation methods.

(Combustion calorific value test)
As an interior material for wall covering, a napped artificial leather is adhered to a calcium silicate board having a thickness of 11 mm and a density of 870 kg/m ³ using a starch/vinyl acetate adhesive (solid content 65 g/m ² ) to produce a composite material. did. This is heated and burned for 20 minutes by a 50kW/m ² heater according to the ISO5660-1 cone calorimeter method, and after 20 minutes, the total calorific value (THR), the maximum calorific value (PHRR), and the peak calorific value of 200kW are exceeded. The maximum average rate of heat dissipation (MARHE) was measured for different times.

(Combustion smoke test)
As the wall wearing interior materials, a thickness of 11 mm, to prepare a composite material by bonding using density 870 kg / m3 nap artificial leather starch-vinyl acetate based adhesive calcium silicate board (solids 65 g / m ²⁾ .. This was heated and burned for 20 minutes by a 50 kW/m ² heater according to the ISO5660-1 cone calorimeter method, and the smoke increase concentration (SPR) was measured.

The above evaluation results are shown in Table 1 below.

[Example 2]
In Example 1, instead of the second polyurethane emulsion containing 10% by weight of the second polyurethane and 28% by weight of the metal salt of dialkylphosphinic acid, 22% by weight of the second polyurethane and 28% by weight of the dialkylphosphine were used. A napped artificial leather was obtained and evaluated in the same manner except that the second polyurethane emulsion containing an acid metal salt was used. The results are shown in Table 1.

[Example 3]
The napped artificial leather in the same manner as in Example 1 except that the napped artificial leather having the first polyurethane content of 19 mass% was used instead of the napped artificial leather having the first polyurethane content of 10 mass %. Obtained and evaluated. The results are shown in Table 1.

[Example 4]
In Example 1, the second polyurethane emulsion in which the particles of the metal salt of dialkylphosphinic acid, which is a phosphorus-based flame retardant, were dispersed was coated at a rate of 60 g/m ² instead of 110 g/m ^2. Other than the above, the napped artificial leather was obtained and evaluated in the same manner. The results are shown in Table 1.

[Example 5]
In Example 1, instead of the non-woven fabric in which fiber bundles containing 25 0.1 dtex ultrafine fibers are three-dimensionally entangled, a non-woven fabric in which fiber bundles containing 6 0.4 dtex ultrafine fibers are three-dimensionally entangled Further, the first polyurethane contains 4,4′-diphenylmethane diisocyanate as a diisocyanate component and replaces the self-emulsifying amorphous polycarbonate urethane having a 100% modulus of 3.0 MPa with an amorphous polycarbonate and a polyisocyanate. A self-emulsifying polyurethane having an ether polyol mass ratio of 60/40 and a 100% modulus of 3.0 MPa was used. A napped artificial leather was obtained and evaluated in the same manner except that the metal salt of alkylphosphinic acid was used. The results are shown in Table 1.

[Example 6]
A napped artificial leather was obtained and evaluated in the same manner as in Example 1, except that the aromatic phosphonate ester shown in Table 1 was used as the phosphorus-based flame retardant particle instead of the metal salt of dialkylphosphinic acid. The results are shown in Table 1.

[Example 7]
A napped artificial leather was obtained and evaluated in the same manner as in Example 1 except that the phosphoric acid ester amides shown in Table 1 were used instead of the metal salt of dialkylphosphinic acid as the phosphorus-based flame retardant particles. The results are shown in Table 1.

[Example 8]
In Example 1, polyethylene and 6-nylon were mixed in a mass ratio of 50/50 and melted, and the molten resin was supplied to the spinneret for mixing and discharged from the nozzle hole. The number of islands was about 600 on average, and the fibers were drawn to obtain 5.5 dtex fibers. This fiber was crimped, cut into 51 mm and carded to obtain a short fiber web having a basis weight of 100 g/m ² . A six-layer superposed web was prepared using a cross-lapper device, sprayed with an oil solution, needle-punched under the conditions of 1500 punch/cm ² , and then hot-pressed to give an apparent density of 0. A fiber entangled body having a thickness of 40 g/cm ³ and a thickness of 1.2 mm was obtained. In addition, as the first polymer elastic body, the diisocyanate component was composed of 4,4′-diphenylmethane diisocyanate, the polymer polyol was composed of a mass ratio of polycarbonate polyol and polyester polyol of 75/25, and the 100% modulus was 5.0 MPa. Polyurethane dissolved in N,N-dimethylformamide at a mass ratio shown in Table 1 was immersed in a mixed solution of N,N-dimethylformamide and water to coagulate, and then toluene was used. The polyethylene was extracted and dried. After that, napped artificial leather was obtained and evaluated in the same manner as in Example 1 except that the dye was changed from dispersion dyeing to gold-containing dyeing. The results are shown in Table 1.

[Example 9]
A napped hair having a thickness of 0.3 mm, a basis weight of 128 g/m ² , and an apparent density of 0.43 g/cm ³ in the same manner as in Example 8 except that the number of stacked short fiber webs was changed from 6 to 4. The artificial leather was obtained and evaluated. The results are shown in Table 1.

[Example 10]
A thickness of 0.55 mm, a basis weight of 300 g/m ² and an apparent density of 0. 1 were obtained in the same manner as in Example 1 except that 10 layers of web were stacked using a cross wrapper device so that the total basis weight was 330 g/m ² . A napped artificial leather having a weight of 54 g/cm ³ was obtained and evaluated. The results are shown in Table 1.

[Example 11]
The same procedure as in Example 1 was repeated except that the web was laminated by 32 layers instead of 8 layers by using the cross-wrapper device, the shrinkage treatment was not performed, and the impregnation treatment was performed so that the content ratio of the first polyurethane was 12% by mass. Then, a napped artificial leather having a thickness of 1.0 mm, a basis weight of 300 g/m ² and an apparent density of 0.30 g/cm ³ was obtained and evaluated. The results are shown in Table 1.

[Comparative Example 1]
In Example 1, instead of the second polyurethane emulsion containing 10% by weight of the second polyurethane and 28% by weight of metal salt of dialkylphosphinic acid, 10% by weight of the second polyurethane and 6.8% by weight. A napped artificial leather was obtained and evaluated in the same manner except that the second polyurethane emulsion containing the metal salt of dialkylphosphinic acid was used. The viscosity of the aqueous dispersion containing the phosphorus-based flame retardant particles and the second elastic polymer was 100 mPa·sec. The results are shown in Table 2.

[Comparative Example 2]
In Example 1, instead of the second polyurethane emulsion containing 10% by mass of the second polyurethane and 28% by mass of the metal salt of dialkylphosphinic acid, 28% by mass of ammonium polyphosphate having a dispersed particle size of 20 μm was contained. The napped artificial leather was obtained and evaluated in the same manner except that the aqueous dispersion was used. The viscosity of the aqueous dispersion containing the phosphorus-based flame retardant particles and the second elastic polymer was 100 mPa·sec. The results are shown in Table 2.

[Comparative Example 3]
In Example 1, the first polyurethane, which is a self-emulsifying amorphous polycarbonate urethane containing 4,4′-dicyclohexylmethane diisocyanate as the diisocyanate component and having a 100% modulus of 3.0 MPa, was used. The first polyurethane, which is a self-emulsifying amorphous polycarbonate urethane made of 6-hexamethylene diisocyanate and having a 100% modulus of 2.0 MPa, is further used as a phosphorus-based flame retardant particle instead of a metal salt of dialkylphosphinic acid. A napped artificial leather was obtained and evaluated in the same manner except that ammonium polyphosphate shown in Table 1 was used. The results are shown in Table 2.

[Comparative Example 4]
A napped artificial leather was obtained and evaluated in the same manner as in Example 1 except that the aromatic phosphoric acid ester shown in Table 1 was used as the phosphorus-based flame retardant particles instead of the metal salt of dialkylphosphinic acid. The results are shown in Table 2. Note that the phosphorus-based flame retardant was treated in the form of an aqueous dispersion during the flame retardant treatment, but when observed in a napped artificial leather, it was not resin-formed into a particulate form.

[Comparative Example 5]
A napped artificial leather was obtained and evaluated in the same manner as in Example 1 except that the number of island components of the spinneret was changed from 25 to 4 and the number of lapped web layers of the napped artificial leather was changed from 8 to 16 layers. .. The results are shown in Table 2.

Referring to Tables 1 and 2, all of the artificial leather substrates obtained in Examples 1 to 11 have good surface quality, have a supple texture, and have good self-extinguishing property. A napped artificial leather having a high level of flame retardancy with low smoke generation and low calorific value of combustion was obtained. On the other hand, the napped artificial leather obtained in Comparative Example 1 in which the phosphorus-based flame retardant particles are few and the flame-retardant particles are present in the interior is inferior in appearance luxury because the phosphorus-based flame retardant is exposed on the surface, and the flame retardancy is high. Was also lacking. In addition, the napped artificial leather obtained in Comparative Example 2 in which ammonium polyphosphate was used for the phosphorus-based flame retardant particles had a poor appearance due to bleeding with time. In addition, the napped artificial leather obtained in Comparative Example 3 had poor flame retardancy, bleeding with time, and poor appearance. Further, in Comparative Example 4 in which the phosphorus-based flame retardant particles were changed to the aromatic phosphate ester, the texture was hard and the flame retardancy was poor. Further, Comparative Example 5 in which the napped artificial leather had a large fineness and a high fabric weight was inferior in flame retardancy.

Claims (10)

A fiber entangled body containing ultrafine fibers having a fineness of 0.5 dtex or less, and a polymer elastic body impregnated into the fiber entangled body, and having a main surface that is a napped surface on which the ultrafine fibers are napped and have a thickness of 0 25-1.5 mm napped artificial leather,
Further comprising phosphorus-based flame retardant particles adhered to the polymeric elastic body that are unevenly distributed in a thickness range of 200 μm or less from the back surface with respect to the main surface,
The basis weight is 100 to 300 g/m ² ,
When the phosphorus-based flame retardant particles have an average particle size of 0.1 to 30 μm, a phosphorus atom content of 14% by mass or more, a solubility in water at 30° C. of 0.2% by mass or less, and a melting point or no melting point. The decomposition temperature is above 150°C,
The napped artificial leather, wherein the content of the phosphorus-based flame retardant particles is 1 to 6 mass% in terms of phosphorus atom conversion content. The napped artificial leather according to claim 1, wherein 90 to 100 mass% of the phosphorus-based flame retardant particles are present in the range of the thickness of 200 µm or less. The napped artificial leather according to claim 1 or 2, wherein the content ratio of the phosphorus-based flame retardant particles in the total amount of the phosphorus-based flame retardant particles and the polymer elastic body is 5 to 20 mass% in terms of phosphorus atoms. .. The polymer elastic body includes a first polymer elastic body existing in the entire thickness section and a second polymer elastic body unevenly distributed in a range of the thickness of 200 μm or less,
The napped artificial leather according to any one of claims 1 to 3, wherein the phosphorus-based flame retardant particles are attached to the second polymeric elastic body. The napped artificial hair according to claim 4, wherein the content ratio of the phosphorus-based flame retardant particles in the total amount of the phosphorus-based flame retardant particles and the second polymer elastic body is 10 to 30 mass% in terms of phosphorus atoms. leather. The said phosphorus flame retardant particle contains at least 1 sort(s) of compound selected from the group which consists of organic phosphinic acid metal salt, aromatic phosphonic acid ester, and phosphoric acid ester amide, The any one of Claims 1-5. Napped artificial leather. A composite material obtained by adhering an interior base material to the back surface of the napped artificial leather according to any one of claims 1 to 6 with an adhesive. The composite material according to claim 7, which has a total calorific value (THR) of 10 MJ/m ² or less. The composite material according to claim 7 or 8, which has a maximum heating value (PHRR) of 250 kW/m ² or less. The maximum average rate of heat dissipation (MARHE) is 90 kW/m< ² > or less, The composite material in any one of Claims 7-9.