Nonwoven fabric

Abstract

A nonwoven fabric including fibers, containing a component A below, a component B below, inside the fibers, wherein the nonwoven fabric includes 50 mass % or more and 95 mass % or less of the component A and 5 mass % or more and 50 mass % or less of the component B with respect to a mass of the whole nonwoven fabric, the fibers included in the nonwoven fabric have a number average fiber diameter of 4 μm or less, the nonwoven fabric has a sheet width of 50 mm or more, the component A is a thermoplastic resin having a solidification point of 100° C. or less, and the component B is a compound having a solidification point higher than a solidification point of the thermoplastic resin having the highest solidification point among the thermoplastic resins and a melting point lower than 150° C.

1 . A method of producing fibers that spins a thermoplastic resin composition including 50 mass % or more and 95 mass % or less of a component A below and 5 mass % or more and 50 mass % or less of a component B′ below with respect to a mass of the whole thermoplastic resin composition with a fiber diameter of 4 μm or less, and the method comprising:
 a process of heating and melting the thermoplastic resin composition (I); and 
 a process of discharging the thermoplastic resin composition from a nozzle (II), 
 wherein the component A is a thermoplastic resin having a solidification point of 100° C. or less, and 
 the component B′ is a compound having a solidification point higher than a solidification point of the thermoplastic resin having the highest solidification point among the thermoplastic resins and a melting point lower than a process temperature. 
 
     
     
         2 . The method of producing fibers according to  claim 1 , wherein in the process (II), a process of spraying a heating fluid is performed. 
     
     
         3 . The method of producing fibers according to  claim 1 ,
 wherein the heating fluid has a temperature higher than the solidification point of the thermoplastic resin having the highest solidification point among the thermoplastic resins included in the component A, and   a difference between the temperature of the heating fluid and the solidification point is 30° C. or more and 200° C. or less.   
     
     
         4 . The method of producing fibers according to  claim 1 , wherein in the process (II), an electrostatic spinning process is performed. 
     
     
         5 . The method of producing fibers according to  claim 1 , wherein in the process (II), a discharge speed of a melt of the thermoplastic resin composition from the nozzle is 0.1 g/minute·nozzle or more and 20 g/minute·nozzle or less. 
     
     
         6 . The method of producing fibers according to  claim 1 , wherein the component A includes a thermoplastic resin having a solidification point of 0° C. or more and 75° C. or less. 
     
     
         7 . The method of producing fibers according to  claim 1 , wherein the process temperature is higher than a melting point of a thermoplastic resin having the highest melting point among the thermoplastic resins, and
 a difference between the process temperature and the melting point is 20° C. or more and 200° C. or less.   
     
     
         8 . The method of producing fibers according to  claim 1 , wherein the thermoplastic resin composition includes either 60 mass % or more and 95 mass % or less of the component A with respect to a whole mass of the thermoplastic resin composition and/or the thermoplastic resin composition includes 10 mass % or more and 40 mass % or less of the component B′ with respect to a whole mass of the thermoplastic resin composition. 
     
     
         9 . The method of producing fibers according to  claim 1 , wherein the fiber has a fiber diameter of 0.1 μm or more and 2 μm or less. 
     
     
         10 . A method of producing a nonwoven fabric, comprising a process of collecting fibers obtained by the method of producing fibers according to  claim 1  and forming the fibers into a sheet shape, wherein the nonwoven fabric has a median fiber diameter of the constituent fibers of 0.1 μm or more and 2 μm or less. 
     
     
         11 . A nonwoven fabric including fibers, comprising:
 a component A below; and   a component B below,   inside the fibers,   wherein the nonwoven fabric includes 50 mass % or more and 95 mass % or less of the component A and 5 mass % or more and 50 mass % or less of the component B with respect to a mass of the whole nonwoven fabric,   the fibers included in the nonwoven fabric have a number average fiber diameter of 4 μm or less,   the nonwoven fabric has a sheet width of 50 mm or more,   the component A is a thermoplastic resin having a solidification point of 100° C. or less, and   the component B is a compound having a solidification point higher than a solidification point of the thermoplastic resin having the highest solidification point among the thermoplastic resins and a melting point lower than 150° C.   
     
     
         12 . The nonwoven fabric according to  claim 11 , wherein the component B includes a compound having a mass average molecular weight of 1 000 g/mol or less, and includes a compound having a mass average molecular weight of 100 g/mol or more and 1 000 g/mol or less. 
     
     
         13 . The nonwoven fabric according to  claim 11 , wherein the component B includes one or two or more selected from fatty acids, higher alcohols, fatty acid amide compounds, polyhydric alcohol organic acid ester compounds, waxes, sphingolipids, alkyl ammonium salts, and fatty acid metal salts, and the component B includes one or two or more selected from fatty acids, higher alcohols, fatty acid amide compounds, polyglyceryl fatty acid ester compounds, sucrose fatty acid ester compounds, and sorbitan fatty acid ester compounds. 
     
     
         14 . The nonwoven fabric according to  claim 11 , wherein the nonwoven fabric has a median fiber diameter of the constituent fibers of 2 μm or less. 
     
     
         15 . The nonwoven fabric according to  claim 11 ,
 wherein the component A includes a thermoplastic resin having a solidification point of 0° C. or more and 75° C. or less, and/or the component A includes a thermoplastic resin having a melting point of 50° C. or more and 150° C. or less.   
     
     
         16 . The nonwoven fabric according to  claim 11 , wherein the nonwoven fabric includes 60 mass % or more and 95 mass % or less of the component A with respect to a mass of the whole nonwoven fabric. 
     
     
         17 . The nonwoven fabric according to  claim 11 , wherein the nonwoven fabric includes 10 mass % or more and 40 mass % or less of the component B with respect to the mass of the whole nonwoven fabric. 
     
     
         18 . The nonwoven fabric according to  claim 11 , wherein the nonwoven fabric has a number average fiber diameter of the constituent fibers of 0.1 μm or more and 3 μm or less, and/or the nonwoven fabric has a median fiber diameter of the constituent fibers of 0.1 μm or more and 2 μm or less. 
     
     
         19 . The nonwoven fabric according to  claim 11 , wherein the nonwoven fabric has a sheet width of 50 mm or more and 3 000 mm or less and/or the nonwoven fabric has “sheet width”/“length perpendicular to sheet width” of 1 or more and 8 or less. 
     
     
         20 . The nonwoven fabric according to  claim 11 ,
 wherein the component A includes one or two or more selected from polycaprolactone, polybutylene succinate, polybutylene succinate adipate, polydioxanone, and polyglycolic acid, and   wherein the component A includes polycaprolactone.