Patent ID: 7141519

Claim:
A nonwoven fabric comprising fibrous material and a binder material, said binder material comprising a binder composition comprising a polymer having the structure: wherein x=1 to about 15 mole percent; y=about 60 to about 99 mole percent; and z=0 to about 30 mole percent; Q is selected from C 1 –C 4 alkyl ammonium, quaternary C 1 –C 4 alkyl ammonium, and benzyl ammonium; Z is selected from —O—, —COO—, —OOC—, —CONH—, and —NHCO—; R 1 , R 2 , R 3 are independently selected from hydrogen and methyl; R 4 is methyl; and R 5 is selected from hydrogen, methyl, ethyl, butyl, ethylhexyl, decyl, dodecyl, hydroxyethyl, hydroxypropyl, polyoxyethylene, and polyoxypropylene; wherein the nonwoven fabric is not dispersible when in an aqueous salt solution comprising about 0.3% to about 10% by weight of a mono or divalent salt, and the nonwoven fabric is dispersible when in water containing up to 200 ppm Ca 2+ and/or Mg 2+ ions.