MIXED FIBER SPUNBONDED NONWOVEN FABRIC, AND METHOD FOR PRODUCTION AND USE THEREOF
A mixed fiber spunbonded nonwoven fabric which comprises 90 to 10% by weight of a long fiber of thermoplastic resin (A) that has been hydrophilization-treated and 10 to 90% by weight of a long fiber of thermoplastic elastomer (B) and which has a strength ratio [the ratio of a strength at 20% of an elongation at a maximum strength (elongation at a maximum point) to the maximum strength] in at least one direction of not more than 40% and a bulk density of 0.10 to 0.40 g/cm 3 . The fabric can exhibit excellent initial hydrophilicity, long-lasting hydrophilicity, liquid dispersibility, liquid transpiration property, moisture permeability, breathability, softness, resistance to fluff, stretchability and touch, and low stickiness, and is suitable for sheets constituting absorbent articles such as sanitary napkins, panty liners, incontinence pads, and disposable diapers. A production method is also provided.
1 . A mixed fiber spunbonded nonwoven fabric which comprises 90 to 10% by weight of a long fiber of thermoplastic resin (A) that has been hydrophilization-treated and 10 to 90% by weight of a long fiber of thermoplastic elastomer (B), wherein the mixed fiber spunbonded nonwoven fabric has a strength ratio [the ratio of a strength at 20% of an elongation at a maximum strength (elongation at a maximum point) to the maximum strength] in at least one direction of not more than 40% and a bulk density of 0.10 to 0.40 g/cm 3 .
2 . The mixed fiber spunbonded nonwoven fabric according to claim 1 , wherein the thermoplastic resin (A) that has been hydrophilization-treated is obtained by adding 0.1 to 10 parts by weight of a nonionic surface-active agent to 100 parts by weight of the thermoplastic resin (A).
3 . The mixed fiber spunbonded nonwoven fabric according to claim 1 , wherein the thermoplastic elastomer (B) is a thermoplastic polyurethane elastomer.
4 . The mixed fiber spunbonded nonwoven fabric according to claim 1 , wherein the thermoplastic resin (A) is a polyolefin.
5 . The mixed fiber spunbonded nonwoven fabric according to claim 4 , wherein the polyolefin is a propylene polymer.
6 . The mixed fiber spunbonded nonwoven fabric according to claim 4 , wherein the polyolefin is an olefin polymer composition comprising 99 to 80% by weight of a propylene polymer and 1 to 20% by weight of a high density polyethylene.
7 . The mixed fiber spunbonded nonwoven fabric according to claim 1 , wherein the mixed fiber spunbonded nonwoven fabric is obtained by stretching in at least one direction.
8 . The mixed fiber spunbonded nonwoven fabric according to claim 1 , wherein by pressing, the mixed fiber spunbonded nonwoven fabric has partially fused long fibers of thermoplastic resin (A) and thermoplastic elastomer (B).
9 . A method for producing a mixed fiber spunbonded nonwoven fabric comprising the steps of partially heat fusing a web which comprises 90 to 10% by weight of a long fiber of thermoplastic resin (A) that has been hydrophilization-treated and 10 to 90% by weight of a long fiber of thermoplastic elastomer (B), stretching the web in at least one direction and relaxing the stretched web, and pressing the relaxed web.
10 . The method for producing a mixed fiber spunbonded nonwoven fabric according to claim 9 , wherein the pressing is carried out on not less than 20% of the area of the relaxed web.
11 . The method for producing a mixed fiber spunbonded nonwoven fabric according to claim 9 , wherein the pressing is carried out at a melting point of the long fiber of thermoplastic resin (A)-100° C. through a melting point of the long fiber of thermoplastic resin (A)-10° C., and at a linear pressure of 20 N/cm or higher.
12 . An absorbent article comprising the mixed fiber spunbonded nonwoven fabric according to claim 1 .
13 . The mixed fiber spunbonded nonwoven fabric according to claim 2 , wherein the thermoplastic elastomer (B) is a thermoplastic polyurethane elastomer.
14 . The mixed fiber spunbonded nonwoven fabric according to claim 2 , wherein the thermoplastic resin (A) is a polyolefin.
15 . The mixed fiber spunbonded nonwoven fabric according to claim 14 , wherein the polyolefin is a propylene polymer.
16 . The mixed fiber spunbonded nonwoven fabric according to claim 14 , wherein the polyolefin is an olefin polymer composition comprising 99 to 80% by weight of a propylene polymer and 1 to 20% by weight of a high density polyethylene.
17 . An absorbent article comprising the mixed fiber spunbonded nonwoven fabric according to claim 2 .
18 . An absorbent article comprising the mixed fiber spunbonded nonwoven fabric according to claim 3 .
19 . An absorbent article comprising the mixed fiber spunbonded nonwoven fabric according to claim 4 .