Amphoteric fluorochemicals for paper

1. A method of imparting oil repellency and grease repellency to a substrate comprising contacting the substrate, which is selected from the group consisting of cellulosic papers, paper products, flexible paper-like nonwoven products, and inorganic materials in fibrous form, with a copolymer prepared from monomers copolymerized in the following percentages by weight:

(a) from about 60% to about 90% of a monomer of Formula 1, or a mixture thereof:

R f -Q-CO—CR═CH 2   Formula 1

wherein:

R f is a straight- or branched-chain perfluoroalkyl group of 2 to about 20 carbon atoms or a mixture thereof,

R is H or CH 3 ,

Q is —(C n H 2n ) p SO 2 NR 1 (C n H 2n O) y —, or —(C n H 2n ) x CONR 1 (C n H 2n O) y —, wherein the —(C n H 2n ) is bonded to R f ,

R 1 is H or C 1 -C 20 alkyl,

each n is independently 1 to about 6, x is 0 to about 4, p is 1 to about 20, and y is 0 to about 4, provided that x+y is a positive integer;

(b) from about 10% to about 25% of a monomer of Formula 2, or a mixture thereof:

CH 2 ═C(R)COZ(CH 2 ) q (CHR) r NR 2 R 3   Formula 2

wherein

R, is H or CH 3 ,

R 2 and R 3 are each independently C 1 -C 4 alkyl, hydroxyethyl, or benzyl or R 2 and R 3 together with the nitrogen atom form a morpholine, pyrrolidine, or piperidine ring,

Z is —O— or —NR 4 —

wherein

R 4 is H or C 1 - C 4 alkyl,

r is 0 to 4, and

q is 1 to 4,

provided that the nitrogen bonded to R 2 and R 3 is from about 0% to 100% salinized, quaternized, or present as amine oxide; and

(c) from about 1% to about 15% of a monomer of Formula 3, or a mixture thereof:

CH 2 ═CR(R 5 ) e —COOH  Formula 3

wherein

R is H or CH 3 ,

R 5 is CO(CH 2 ) 5 , CO—O—(CH 2 ) 2 , C 6 H 4 CHR, or CONRR 6 ,

R 6 is C 6 H 4 OCH 2 , (CH 2 ) d , or C(CH 3 ) 2 CH 2 ,

d is 1 to about 10, and

e is 0 or 1,

provided that when Formula 1 is

F(CF 2 CF 2 ) m C 2 H 4 SO 2 N(CH 3 )C 2 H 4 OC (O)C(R)═CH 2

wherein

m is from about 1 to about 10,

then Formula 3 is present at a minimum of about 4% by weight.

2. The method of claim 1 wherein the composition is an aqueous dispersion.

3. The method of claim 1 wherein for Formula 1, R f is a straight- or branched-chain perfluoroalkyl group of 2 to about 20 carbon atoms or a mixture thereof.

4. The method of claim 3 wherein R f is a perfluoroalkyl group of 2 to about 6 carbon atoms or a mixture thereof.

5. The method of claim 1 wherein Formula 1 is

F(CF 2 CF 2 ) m C 2 H 4 SO 2 N(CH 3 )C 2 H 4 OC(O)C(R)═CH 2

wherein

m is 1 to 3 or a mixture thereof, and

R is H or CH 3 .

6. The method of claim 1 wherein Formula 2 is diethylaminoethyl (meth)acrylate or dimethylaminoethyl (methacrylate).

7. The method of claim 1 wherein Formula 3 is acrylic acid or methacrylic acid.

8. The method of claim 1 wherein the composition further comprises at least one of the monomers glycidyl (meth)acrylate, vinylidene chloride, alkyl (meth)acrylate, hydroxyalkylene (meth)acrylate or vinyl acetate.

9. The method of claim 1 wherein the contacting is external onto the substrate surface, or is internal into the substrate.

10. The method of claim 1 wherein the composition is contacted with the substrate surface in an amount of from about 0.05% to about 0.35% fluorine by weight percent of the substrate.

11. The method of claim 1 wherein the composition is added internally into the substrate in an amount of from about 0.2% to about 0.45% fluorine by weight of the substrate.

12. A substrate treated by the method of claim 1 .

13. An improved process for the preparation of an amphoteric fluorochemical copolymer made from a mixture of monomers of a) Formula 1, b) Formula 2, and c) Formula 3, wherein

(a) Formula 1 is

R f -Q-CO—CR═CH 2   Formula 1

wherein:

R f is a straight- or branched-chain perfluoroalkyl group of 2 to about 20 carbon atoms,

R is H or CH 3 ,

Q is —(C n H 2n ) x (C n H 2n O) y —, —(C n H 2n ) p SO 2 NR 1 (C n H 2n O) y —, or —(C n H 2n ) x CONR 1 (C n H 2n O) y —, wherein the —(C n H 2n ) is bonded to R f ,

R 1 is H or C 1 -C 20 alkyl,

each n is independently 1 to about 6, x is 0 to about 4, p is 1 to about 20, y is 0 to about 4, provided that x +y is a positive integer;

(b) Formula 2 is

CH 2 ═C(R)COZ(CH 2 ) q (CHR) r NR 2 R 3   Formula 2

wherein

R is H or CH 3 ,

R 2 and R 3 are each independently C 1 -C 4 alkyl, hydroxyethyl, or benzyl or

R 2 and R 3 together with the nitrogen atom form a morpholine, pyrrolidine, or piperidine ring,

Z is —O— or —NR 4 —

Wherein

R 4 is H or C 1 -C 4 alkyl,

r is 0 to 4, and

q is 1 to 4,

provided that the nitrogen bonded to R 2 and R 3 is from about 0% to 100% salinized, quaternized, or present as amine oxide; and

(c) Formula 3 is

CH 2 ═CR(R 5 ) e —COOH  Formula 3

wherein

R is H or CH 3 ,

R 5 is CO(CH 2 ) 5 , CO—O—(CH 2 ) 2 , C 6 H 4 CHR, or CONRR 6 ,

R 6 is C 6 H 4 OCH 2 , (CH 2 ) d , or C(CH 3 ) 2 CH 2 ,

d is 1 to about 10, and

e is 0 or 1,

wherein the improvement comprises avoiding gel formation by delaying addition of Formula 3 to the mixture until after said mixture has reached a temperature of from about 60° C. to about 75° C.

14. The process of claim 13 wherein the solvent is a mixture of methylisobutyl ketone and isopropyl alcohol.

15. The process of claim 13 wherein Formula 3 is injected into the mixture when said mixture is under an inert atmosphere.

16. The process of claim 13 wherein Formula 3 is injected together with an optional monomer.

17. The process of claim 13 wherein the optional monomer is at least one of the monomers glycidyl (meth)acrylate, vinylidene chloride, an alkyl (meth)acrylate, a hydroxyalkylene (meth)acrylate, or a vinyl acetate.

18. A copolymer comprising monomers copolymerized in the following percentages by weight:

(a) from about 60% to about 90% of a monomer of Formula 1A or a mixture thereof:

R f -Q-CO—CR═CH 2   Formula 1A

wherein:

R f is a straight- or branched-chain perfluoroalkyl group of 2 to about 20 carbon atoms,

R is H or CH 3 ,

Q is —(C n H 2n ) p SO 2 NR 1 (C n H 2n O) y —, wherein the —(C n H 2n ) is bonded to R f ,

R 1 is H or C 1 -C 20 alkyl and

each n is independently 1 to about 6,

p is 1 to about 20, and y is 0 to about 4,

(b) from about 10% to about 25% of a monomer of Formula 2 or a mixture thereof:

CH 2 ═C(R)COZ(CH 2 ) q (CHR) r NR 2 R 3   Formula 2

wherein

R is H or CH 3,

R 2 and R 3 are each independently C 1 - C 4 alkyl, hydroxyethyl, or benzyl or R 2 and R 3 together with the nitrogen atom form a morpholine, pyrrolidine, or piperidine ring,

Z is —O— or —NR 4 — wherein R 4 is H or C 1 - C 4 alkyl,

r is 0 to 4,

q is 1 to 4 and

provided that the nitrogen bonded to R 2 and R 3 is from about 0% to 100% salinized, quaternized, or present as amine oxide; and

(c) from about 1% to about 15% of a monomer of Formula 3 or a mixture thereof:

CH 2 ═CR(R 5 ) e —COOH  Formula 3

wherein

R is H or CH 3 ,

R 5 is CO(CH 2 ) 5 , CO—O—(CH 2 ) 2 , C 6 H 4 CHR, or CONRR 6 ,

R 6 is C 6 H 4 OCH 2 , (CH 2 ) d , or C(CH 3 ) 2 CH 2 ,

d is 1 to about 10, and

e is 0 or 1,

provided that when Formula 1 is

F(CF 2 CF 2 ) m C 2 H 4 SO 2 N(CH 3 )C 2 H 4 OC(O)C(R)═CH 2

wherein

m is from about 1 to about 10,

then Formula 3 is present at a minimum of about 4% by weight, said copolymer capable of imparting oil repellency and grease repellency to a flexible, fibrous nonwoven substrate.

19. A copolymer of claim 18 wherein R f is a perfluoroalkyl group of 2 to about 6 carbon atoms.

20. A copolymer of claim 18 wherein Formula 1 is

F(CF 2 CF 2 ) m C 2 H 4 SO 2 N(CH 3 )C 2 H 4 OC(O)C(R)═CH 2

wherein

m is 2 or 3 or a mixture thereof, and

R is H or CH 3 .

21. A copolymer of claim 18 wherein Formula 2 is diethylaminoethyl (meth)acrylate or dimethylaminoethyl (methacrylate).

22. A copolymer of claim 18 wherein Formula 3 is acrylic acid or methacrylic acid.

23. A copolymer of claim 18 wherein the composition further comprises at least one of the monomers glycidyl (meth)acrylate, vinylidene chloride, alkyl (meth)acrylate, hydroxyalkylene (meth)acrylate, or vinyl acetate.