Napped artificial leather and composite material

Abstract

Disclosed is a napped artificial leather including: a fiber-entangled body including ultrafine fibers having a fineness of 0.5 dtex or less; and an elastic polymer impregnated into the fiber-entangled body, the napped artificial leather having a thickness of 0.25 to 1.5 mm, and including a main surface that is a napped surface formed by napping the ultrafine fibers. The napped artificial leather further includes phosphorous-based flame retard ant particles attached to the elastic polymer such as a polyurethane, the phosphorous-based flame retardant particles being locally present in a range of a thickness of 200 pm or less from a back surface opposite to the main surface. The phosphorous-based flame retardant particles have an average particle size of 0.1 to 30 μm, a phosphorus atom content of 14 mass % or more, and a solubility in water at 30° C. of 0.2 mass % or less, and a melting point, or, in the absence of a melting point, a decomposition temperature, of 150° C. or more, and a content ratio of the phosphorous-based flame retardant particles is 1 to 6 mass % as a content ratio in terms of phosphorus atoms.

1 . A napped artificial leather comprising:
 a fiber-entangled body comprising ultrafine fibers having a fineness of 0.5 dtex or less;   an elastic polymer impregnated into the fiber-entangled body; and   phosphorous-based flame retardant particles attached to the elastic polymer;   wherein:   the napped artificial leather having has a thickness of 0.25 to 1.5 mm;   the napped artificial leather comprises including a main surface that is a napped surface formed by napping the ultrafine fibers and a back surface opposite to the main surface;   the phosphorous-based flame retardant particles are locally present in a range of a thickness of 200 μm or less from the back surface;   the phosphorous-based flame retardant particles have an average particle size 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, and a melting point, or, in the absence of a melting point, a decomposition temperature, of 150° C. or more; and   a content ratio of the phosphorous-based flame retardant particles in the napped artificial leather is 1 to 6 mass % as a content ratio in terms of phosphorus atoms.   
     
     
         2 . The napped artificial leather according to  claim 1 , wherein:
 the elastic polymer comprises a polyurethane that is a reaction product of a polyurethane raw material comprising a polymer polyol, an organic polyisocyanate, and a chain extender;   the polymer polyol comprises 60 mass % or more of a polycarbonate polyol, and has an average number of repeating carbon atoms excluding a reactive functional group, of 6.5 or less; and   the organic polyisocyanate comprises at least one selected from the group consisting of 4,4′-dicyclohexylmethane diisocyanate and 4,4′-diphenylmethane diisocyanate.   
     
     
         3 . The napped artificial leather according to  claim 1 , wherein the napped artificial leather has a basis weight of 100 to 300 g/m 2 . 
     
     
         4 . The napped artificial leather according to  claim 1 , wherein the phosphorous-based flame retardant particles include comprise at least one compound selected from the group consisting of an organic phosphinic acid metal salt, an aromatic phosphonic acid ester, and a phosphoric acid ester amide. 
     
     
         5 . The napped artificial leather according to  claim 1 , wherein the phosphorous-based flame retardant particles comprise at least one selected from the group consisting of a dialkyl phosphinic acid metal salt and a monoalkyl phosphinic acid metal salt. 
     
     
         6 . The napped artificial leather according to  claim 1 , wherein 90 to 100 mass % of the phosphorous-based flame retardant particles are present in the range of a thickness of 200 μm or less from the back surface. 
     
     
         7 . The napped artificial leather according to  claim 1 , wherein a ratio of a thickness of a region of the napped artificial leather in which the phosphorous-based flame retardant particles are locally present to an overall thickness of the napped artificial leather is 10 to 60%. 
     
     
         8 . The napped artificial leather according to  claim 1 , wherein a content ratio of the phosphorous-based flame retardant particles relative to a total amount of the phosphorous-based flame retardant particles and the elastic polymer is 5 to 20 mass % in terms of phosphorus atoms. 
     
     
         9 . The napped artificial leather according to  claim 1 , wherein:
 the elastic polymer comprises a first elastic polymer that is present throughout a thickness cross section of the napped artificial leather, and a second elastic polymer that is locally present in the range of a thickness of 200 um or less from the back surface; and   the phosphorous-based flame retardant particles are attached to the second elastic polymer.   
     
     
         10 . The napped artificial leather according to  claim 9 , wherein a content ratio of the phosphorous-based flame retardant particles relative to a total amount of the phosphorous-based flame retardant particles and the second elastic polymer is 10 to 30 mass % in terms of phosphorus atoms. 
     
     
         11 . A composite material comprising:
 the napped artificial leather according to  claim 1 ; and   an interior backing material bonded to the back surface of the napped artificial leather with an adhesive.   
     
     
         12 . The composite material according to  claim 11 , wherein the composite material has a total heat release (THR) of 10 MJ/m 2  or less. 
     
     
         13 . The composite material according to  claim 11 , wherein the composite material has a peak heat release rate (PHRR) of 250 kW/m 2  or less. 
     
     
         14 . The composite material according to  claim 11 , wherein the composite material has a maximum average rate of heat emission (MARHE) of 90 kW/m 2  or less. 
     
     
         15 . The napped artificial leather according to  claim 2 , wherein the phosphorous-based flame retardant particles comprise at least one selected from the group consisting of a dialkyl phosphinic acid metal salt and a monoalkyl phosphinic acid metal salt. 
     
     
         16 . The napped artificial leather according to  claim 6 , wherein the phosphorous-based flame retardant particles comprise at least one selected from the group consisting of a dialkyl phosphinic acid metal salt and a monoalkyl phosphinic acid metal salt. 
     
     
         17 . The napped artificial leather according to  claim 7 , wherein the phosphorous-based flame retardant particles comprise at least one selected from the group consisting of a dialkyl phosphinic acid metal salt and a monoalkyl phosphinic acid metal salt. 
     
     
         18 . The napped artificial leather according to  claim 9 , wherein the phosphorous-based flame retardant particles comprise at least one selected from the group consisting of a dialkyl phosphinic acid metal salt and a monoalkyl phosphinic acid metal salt.