Laminated nonwoven fabric

Abstract

An object of the present invention is to provide a nonwoven fabric having high tensile strength and high tear strength. The laminate nonwoven fabric of the present invention is a laminated nonwoven fabric obtained by thermally press-contacting a thermoplastic continuous fiber layer as an outer layer with both surfaces of an interlayer, wherein the ratio (F1/F2) between the average oblateness (F1) of the thermoplastic continuous fiber present on the surface side and the average oblateness (F2) of the thermoplastic continuous fiber present on the inner side is 1.20 or more.

1 - 15 . (canceled) 
     
     
         16 . A laminated nonwoven fabric obtained by thermally press-contacting a thermoplastic continuous fiber layer as an outer layer with both surfaces of an interlayer, wherein the ratio (F1/F2) between the average oblateness (F1) of the thermoplastic continuous fiber present on the surface side and the average oblateness (F2) of the thermoplastic continuous fiber present on the inner side is 1.2 or more. 
     
     
         17 . The laminated nonwoven fabric according to  claim 16 , wherein the interlayer contains at least one or more thermoplastic ultrafine fiber layers. 
     
     
         18 . The laminated nonwoven fabric according to  claim 16 , wherein the average oblateness (F2) of the thermoplastic continuous fiber present on the inner side is from 0.1 to 0.8. 
     
     
         19 . The laminated nonwoven fabric according to  claim 17 , wherein the fiber diameter of the thermoplastic continuous fiber is from 5 to 30 μm and the fiber diameter of the thermoplastic ultrafine fiber is from 0.5 to 10 μm. 
     
     
         20 . The laminated nonwoven fabric according to  claim 16 , wherein the total thickness of the laminated nonwoven fabric is from 15 to 300 μm. 
     
     
         21 . The laminated nonwoven fabric according to  claim 16 , wherein the total basis weight of the laminated nonwoven fabric is from 10 to 250 g/m 2 . 
     
     
         22 . The laminated nonwoven fabric according to  claim 16 , wherein the outer layer surface is bonded over the entire surface. 
     
     
         23 . The laminated nonwoven fabric according to  claim 17 , wherein the content ratio of the thermoplastic ultrafine fiber is from 5 to 40 wt %. 
     
     
         24 . The laminated nonwoven fabric according to  claim 16 , wherein the tensile strength in the machine direction per unit basis weight is 1.00 (N/1.5 cm)/(g/m 2 ) or more and the tear strength in the machine direction per unit basis weight is 0.04 N/(g/m 2 ) or more. 
     
     
         25 . The laminated nonwoven fabric according to  claim 16 , wherein the resin component constituting the thermoplastic continuous fiber is present in a state of forming a structure except for a sheath-core structure. 
     
     
         26 . The laminated nonwoven fabric according to  claim 17 , wherein the thermoplastic continuous fiber and the thermoplastic ultrafine fiber are composed of a single component. 
     
     
         27 . The laminated nonwoven fabric according to  claim 17 , wherein the thermoplastic continuous fiber and the thermoplastic ultrafine fiber are composed of a polyester-based resin or a polyamide-based resin. 
     
     
         28 . A method for producing the laminated nonwoven fabric according to  claim 17 , comprising a step of, after a thermoplastic continuous fiber layer is stacked on both surfaces of a thermoplastic ultrafine fiber layer, pressurizing and thermally press-contacting the surfaces one by one in two stages between a flat rigid heated roll and a non-heated elastic roll having a Shore hardness D of 60 to 95 under a surface pressure of 30 to 200 kg/cm 2  by setting the rigid heated roll temperature to a temperature 5° C. or more lower than the melting point of the resin constituting the thermoplastic continuous fiber, wherein a step of rapidly cooling the laminate is provided between said pressurizing and thermally press-contacting steps in two stages. 
     
     
         29 . A composite membrane support comprising the laminated nonwoven fabric according to  claim 16 . 
     
     
         30 . A composite membrane obtained by forming a porous layer and a dense layer (skin layer) having a separation function, on the composite membrane support according to  claim 29 .