Nonwoven fabric

Abstract

Disclosed is a nonwoven fabric formed from (i) a nonwoven fabric substrate and (ii) a fluorine-containing polymer adhering to the nonwoven fabric substrate, wherein the fluorine-containing polymer contains: (a) repeating units formed from a fluorine-containing monomer which is alpha-chloro acrylate or alpha-chloro acrylamide containing a fluoroalkyl group, and (b) repeating units formed from a halogenated olefin monomer, and the fluorine-containing polymer is free from repeating units formed from a (meth)acrylate containing a linear or branched hydrocarbon group having at least 18 carbon atoms.

1 . A nonwoven fabric comprising (i) a nonwoven fabric substrate and (ii) a fluorine-containing polymer adhering to the nonwoven fabric substrate,
 wherein the fluorine-containing polymer comprises:   (a) repeating units formed from a fluorine-containing monomer which is alpha-chloro acrylate or alpha-chloro acrylamide containing a fluoroalkyl group, and   (b) repeating units formed from a halogenated olefin monomer, and   the fluorine-containing polymer is free from repeating units formed from a (meth)acrylate containing a linear or branched hydrocarbon group having at least 18 carbon atoms.   
     
     
         2 . The nonwoven fabric according to  claim 1 , wherein the fluorine-containing monomer (a) is a compound represented by the formula:
   CH 2 ═C(—Cl)—C(═O)—Y—Z—Rf
   wherein Y is —O— or —NH—;   Z is a direct bond or divalent organic group; and   Rf is a fluoroalkyl group having 1 to 20 carbon atoms.   
     
     
         3 . The nonwoven fabric according to  claim 1 , wherein Z is a direct bond, a linear or branched aliphatic group having 1-20 carbon atoms,
 an aromatic group or cycloaliphatic group having 6-18 carbon atoms,   a group represented by the formula —R 2 (R 1 )N—SO 2 — or the formula —R 2 (R 1 )N—CO—   wherein R 1  is an alkyl group having 1 to 10 carbon atoms and R 2  is a linear alkylene group or branched alkylene group having 1 to 10 carbon atoms, for example, by a —CH 2 CH 2 N(R 1 )SO 2 — group wherein R 1  is an alkyl group having 1 to 4 carbon atoms,   a group represented by the formula —CH 2 CH(OR 3 )CH 2 —[Ar—(O) q ] p — wherein R 3  is a hydrogen atom or an acyl group having 1 to 10 carbon atoms, Ar is an arylene group optionally having a substituent group, p is 0 or 1, and q is 0 or 1,   a group represented by the formula —(CH 2 ) n —Ar—(O) q — (wherein Ar is an arylene group optionally having a substituent group, n is 0-10, and q is 0 or 1), or   a —(CH 2 ) m —SO 2 —(CH 2 ) n — group or a —(CH 2 ) m —S—(CH 2 ) n — group wherein m is 1-10, and   n is 0-10.   
     
     
         4 . The nonwoven fabric according to  claim 1 , wherein the halogenated olefin monomer (b) is an olefin having 2-20 carbon atoms and substituted by 1-10 chlorine atoms, bromine atoms or iodine atoms. 
     
     
         5 . The nonwoven fabric according to  claim 4 , wherein the halogenated olefin monomer (b) is at least one selected from the group consisting of vinyl chloride and vinylidene chloride. 
     
     
         6 . The nonwoven fabric according to  claim 1 , wherein the fluorine-containing polymer further comprises a fluorine-free non-crosslinkable monomer, and
 the fluorine-free non-crosslinkable monomer is at least one selected from the group consisting of:   (c1-i) repeating units formed from a (meth)acrylate or (meth)acrylamide monomer containing a linear or branched hydrocarbon group having 17 or less carbon atoms, and   (c1-ii) repeating units formed from a (meth)acrylate or (meth)acrylamide monomer containing a cyclic hydrocarbon group.   
     
     
         7 . The nonwoven fabric according to  claim 6 , wherein the (meth)acrylate or (meth)acrylamide monomers (c1-i) and (c1-ii) are a compound represented by the formula:
   CH 2 ═CA-T
   wherein A is a hydrogen atom, a methyl group, or a halogen atom other than a fluorine atom,   T is an open-chain or cyclic organic group having 1 to 31 carbon atoms and an ester bond or amide bond.   
     
     
         8 . The nonwoven fabric according to  claim 6 , wherein the (meth)acrylate or (meth)acrylamide monomer containing a linear or branched hydrocarbon group having 17 or less carbon atoms (c1-i) is an acrylate represented by the formula:
   CH 2 ═CA 1 CO—Z 1 -A 2  
   wherein A 1  is a hydrogen atom, a methyl group, or a halogen atom other than a fluorine atom,   Z 1  is —O— or —NH—, and   A 2  is an alkyl group represented by C n H 2n+1  wherein n is 1 to 17.   
     
     
         9 . The nonwoven fabric according to  claim 1 , wherein the fluorine-containing polymer further comprises:
 (c2) repeating units formed from a fluorine-free crosslinking (meth)acrylate or (meth)acrylamide monomer.   
     
     
         10 . The nonwoven fabric according to  claim 1 , wherein the nonwoven fabric substrate is a combination of natural fibers and synthetic fibers, 
     
     
         11 . The nonwoven fabric according to  claim 10 , wherein the nonwoven fabric substrate is a combination of cellulosic fibers and polyester fibers. 
     
     
         12 . The nonwoven fabric according to  claim 10 , wherein the weight ratio of the natural fiber to the synthetic fiber is 15:85-45:55. 
     
     
         13 . The nonwoven fabric according to  claim 1 , wherein the amount of the fluorine-containing monomer (a) is 20% to 90% by weight, based on the fluorine-containing polymer, and
 the amount of the halogenated olefin monomer (b) is 5 to 300 parts by weight, based on 100 parts by weight of the fluorine-containing monomer (a).   
     
     
         14 . The nonwoven fabric according to  claim 6 , wherein the amount of each of the fluorine-free non-crosslinkable monomers (c1-i) and (c1-ii) is 0 to 500 parts by weight, based on 100 parts by weight of the fluorine-containing monomer (a). 
     
     
         15 . The nonwoven fabric according to  claim 1 , wherein the amount of the fluorine-containing polymer adhering to the nonwoven fabric substrate is 0.01 to 5 parts by weight, based on 100 parts by weight of the nonwoven fabric substrate. 
     
     
         16 . A method of producing the nonwoven fabric according to  claim 1 , which comprises applying the fluorine-containing polymer to the nonwoven fabric substrate. 
     
     
         17 . The method according to  claim 16 , wherein the fluorine-containing polymer is in the form of an aqueous dispersion.