Liquid impermeable nonwoven sheet for absorbent article

Abstract

A liquid impermeable sheet comprising a melt blown non woven fabric and an absorbent article using liquid impermeable sheet are provided. The melt blown non woven fabric comprises ultra fine fibers of thermoplastic polymer spun by a melt blowing method, and the fiber diameter is 10 μm or less. The melt blown non woven fabric satisfies the following Formulas (A): 2≦W/D 2 ≦200 and (B): 0.05≦d≦0.2 where W is basis weight (g/m 2 ), D is fiber diameter (μtm) and d is apparent density of the non woven fabric (g/cc), and thus, the fabric is excellent in feeling, flexibility and air permeability, while it keeps its liquid impermeability.

1 . A liquid impermeable sheet for an absorbent article, comprising a melt blown non-woven fabric comprising ultra fine fibers of thermoplastic polymer, the polymer being spun by a melt blowing method and the fiber diameter being 10 μm at most, the melt blown non-woven fabric satisfying the following Formulas A and B, 
       2≦ W/D   2 ≦200  (A)19.05 ≦d≦ 0.2  (B) 
       where W is basis weight (g/m 2 ), D is fiber diameter (μm), and d is apparent density of the non-woven fabric (g/cc).  
     
     
         2 . The liquid impermeable sheet for an absorbent article according to  claim 1 , further comprising a fiber non-woven fabric of thermoplastic polymer laminated on the melt blown non-woven fabric.  
     
     
         3 . The liquid impermeable sheet for an absorbent article according to  claim 1 , wherein the melt blown non-woven fabric comprises thermoplastic ultra thin conjugated fibers whose diameter is 10 μm at most, and the fiber is provided by conjugating a low melting point polymer and a high melting point polymer, the difference in the melting points between the polymers being at least 15° C.  
     
     
         4 . The liquid impermeable sheet for an absorbent article according to  claim 1 , wherein the melt blown non-woven fabric is a combined material of thermoplastic ultra fine fibers whose diameter is 10,μm at most, and the fibers comprise a low melting point polymer and a high melting point polymer, the difference in the melting points between the polymers being at least 15° C.  
     
     
         5 . The liquid impermeable sheet for an absorbent article according to  claim 1 , wherein the liquid impermeable sheet is formed as a sheet selected from the group consisting of a back sheet, a side sheet, a round sheet and a waist gather for an absorbent article.  
     
     
         6 . The liquid impermeable sheet for an absorbent article according to  claim 1 , wherein the melt blown non-woven fabric comprises at least one polymer selected from the group consisting of a polyolefin polymer and a polyester polymer.  
     
     
         7 . The liquid impermeable sheet for an absorbent article according to  claim 1 , wherein the fibers composing the melt blown non-woven fabric are at least one fiber selected from the group consisting of single fiber, fiber formed by conjugating a low melting point polymer and a high melting point polymer, and fiber formed by combining a low melting point polymer and a high melting point polymer.  
     
     
         8 . The liquid impermeable sheet for an absorbent article according to  claim 1 , wherein the average fiber diameter of the melt blown non-woven fabric is 0.1-9 μm.  
     
     
         9 . The liquid impermeable sheet for an absorbent article according to  claim 1 , wherein the basis weight of the melt blown non-woven fabric is 4-50 g/m 2 .  
     
     
         10 . The liquid impermeable sheet for an absorbent article according to  claim 2 , wherein the thermoplastic fiber non-woven fabric is a non-woven fabric comprising at least one fiber selected from the group consisting of filament and staple fiber.  
     
     
         11 . The liquid impermeable sheet for an absorbent article according to  claim 10 , wherein the thermoplastic fiber non-woven fabric comprises a two-composition conjugated fiber formed by conjugating a low melting point polymer and a high melting point polymer.  
     
     
         12 . The liquid impermeable sheet for an absorbent article according to  claim 11 , wherein the difference in the melting points between the high melting point polymer and the low melting point polymer is at least 15° C.  
     
     
         13 . The liquid impermeable sheet for an absorbent article according to  claim 11 , wherein the conjugated fiber is at least one fiber selected from the group consisting of sheath-core type fiber, eccentric sheath-core type fiber, parallel type fiber, multilayer type fiber and sea-island type fiber.  
     
     
         14 . The liquid impermeable sheet for an absorbent article according to  claim 11 , wherein the polymer composition composing the conjugated fiber is at least one polymer selected from the group consisting of polyolefins, polyesters and polyamides.  
     
     
         15 . The liquid impermeable sheet for an absorbent article according to  claim 10 , wherein the fineness of the single fiber composing the non-woven fabric is 0.5-10 d/f.  
     
     
         16 . The liquid impermeable sheet for an absorbent article according to  claim 10 , wherein the length of the staple fiber composing the non-woven fabric is 3-51 mm.  
     
     
         17 . The liquid impermeable sheet for an absorbent article according to  claim 10 , wherein the staple fiber composing the non-woven fabric is at least one fiber selected from the group consisting of crimped fiber and uncrimped fiber.  
     
     
         18 . The liquid impermeable sheet for an absorbent article according to  claim 2 , wherein the cross section of the fiber is at least one shape selected from the group consisting of circular, modified, and hollow.  
     
     
         19 . The liquid impermeable sheet for an absorbent article according to  claim 2 , wherein the melt blown non-woven fabric and the fiber non-woven fabric for lamination are laminated by using at least one bonding method selected from the group consisting of a heat bonding by embossed rollers, an ultrasonic welding, a hot air cycle bonding using hot air blown at a temperature within the range between the melting points of the high melting point polymer and the low melting point polymer, and a hot melt bonding using a hot melt polymer.  
     
     
         20 . An absorbent article comprising the liquid impermeable sheet according to claim  1 .