Water/oil repellant composition, article and process for producing article

1. A water/oil repellent composition, comprising:

(A) a copolymer (A) comprising from 40 to 95 mass % of units based on a monomer (a1), from 1 to 60 mass % of units based on a monomer (a2), and from 0 to less than 5 mass % of units based on a monomer (a3);

(B) a copolymer (B) comprising from 40 to 91 mass % of units based on a monomer (b1), from 2 to 20 mass % of units based on a monomer (b2), from 5 to 20 mass % of units based on a monomer (b3), and from 2 to 20 mass % of units based on a monomer (b4); and

(C) a liquid medium (C),

wherein:

the monomer (a1) is a unit represented by the formula (1):

(Z—Y) n X  (1);

the monomer (a2) is a vinylidene chloride unit or a vinylidene fluoride unit;

the monomer (a3) is an acrylate or methacrylate unit comprising a saturated hydrocarbon group having at least 12 carbon atoms;

the monomer (b1) is a unit represented by the formula (1) above;

the monomer (b2) is a vinylidene chloride unit or a vinylidene fluoride unit;

the monomer (b3) is an acrylate or methacrylate unit comprising a saturated hydrocarbon group having at least 12 carbon atoms;

the monomer (b4) is a vinyl chloride unit;

Z is a C 1-6 polyfluoroalkyl group or any one of formulae (2-1) to (2-3):

C i F 2i+1 O(CFX 1 CF 2 O) j CFX 2 —  (2-1)

C i F 2i+1 [CH 2 CF 2 ] v —  (2-2)

C i F 2i+1 [CH 2 CF 2 ] v [CF 2 CF 2 ] r —  (2-3);

Y is a divalent organic group having no fluorine atom, or a single bond;

n is 1 or 2;

X is, when n is 1, a group represented by any one of formulae (3-1) to (3-5):

—CR 2 ═CH 2   (3-1)

—C(O)OCR 2 ═CH 2   (3-2)

—OC(O)CR 2 ═CH 2   (3-3)

—OCH 2 -φ-CR 2 ═CH 2   (3-4)

—OCH═CH 2   (3-5);

X is, when n is 2, a group represented by any one of following formulae (4-1) to (4-4):

—CH[—(CH 2 ) m CR 3 ═CH 2 ]-  (4-1)

—CH[—(CH 2 ) m C(O)OCR 3 ═CH 2 ]—  (4-2)

—CH[—(CH 2 ) m OC(O)CR 3 ═CH 2 ]—  (4-3)

—OC(O)CH═CHC(O)O—  (4-4);

i is an integer of from 1 to 6;

j is an integer of from 0 to 10;

v is an integer of from 1 to 4;

r is an integer of from 1 to 3;

each of X 1 and X 2 are independently a fluorine atom or a trifluoromethyl group;

R 2 is a hydrogen atom, a methyl group or a halogen atom;

φ is a phenylene grown;

R 3 is a hydrogen atom, a methyl group or a halogen atom; and

m is an integer of from 0 to 4.

2. The water/oil repellent composition according to claim 1 , wherein:

Z is a C 4-6 perfluoroalkyl group;

Y is a C 1-4 alkylene group;

n is 1;

X is —C(O)OCR 2 ═CH 2 ; and

R 2 is a hydrogen atom, a methyl group, a fluorine atom or a chlorine atom.

3. The water/oil repellent composition according to claim 1 , wherein a proportion of the copolymer (A) is from 20 to 90 mass %, and a proportion of the copolymer (B) is from 10 to 80 mass %, relative to a total mass of the copolymer (A) and the copolymer (B).

4. The water/oil repellent composition according to claim 1 , wherein the copolymer (A) further comprises units based on a monomer (a4), which is a vinyl chloride unit.

5. The water/oil repellent composition according to claim 1 , wherein the copolymer (A) further comprises units based on a monomer (a5) having no polyfluoroalkyl group and having a crosslinkable functional group.

6. The water/oil repellent composition according to claim 1 , wherein the copolymer (B) further comprises units based on a monomer (b5), having no polyfluoroalkyl group and having a crosslinkable functional group.

7. The water/oil repellent composition according to claim 1 , wherein:

a mass average molecular weight (Mw) of the copolymer (A) is larger than a mass average molecular weight (Mw) of the copolymer (B), and a difference is from 5,000 to 400,000; or

a number average molecular weight (Mn) of the copolymer (A) is larger than a number average molecular weight (Mn) of the copolymer (B), and a difference is from 2,000 to 50,000.

8. The water/oil repellent composition according to claim 1 , wherein a difference between a content (mass %) of units based on the monomer (a3) in the copolymer (A) and a content (mass %) of units based on the monomer (b3) in the copolymer (B) is at least 2 (mass %).

9. The water/oil repellent composition according to claim 1 , wherein R 2 in either the units based on the monomer (a1) in the copolymer (A) or the units based on the monomer (b1) in the copolymer (A) is a hydrogen atom or a methyl group, and R 2 in the other is a fluorine atom or a chlorine atom.

10. An article, comprising a porous substrate, wherein the porous substrate has a water/oil repellent-treated surface treated with the water/oil repellent composition of claim 1 on at least one side, and has a moisture-permeable waterproofing film on one side.

11. The article according to claim 10 , wherein the treated porous substrate has water/oil repellent-treated surfaces on both sides, and has the moisture-permeable waterproofing film on one water/oil-repellent treated surface.

12. The article according to claim 10 , wherein the porous substrate is a fabric.

13. A process for producing an article having a porous substrate, the process comprising:

treating at least one side of a porous substrate with the water/oil repellent composition of claim 1 to form a water/oil repellent-treated surface; and

applying a coating liquid comprising a material adapted to form a moisture-permeable waterproofing film to one side of the porous substrate to form the moisture-permeable waterproofing film.

14. The process according to claim 13 , wherein the water/oil repellent-treated surface is formed on both sides of the substrate, and then the moisture-permeable waterproofing film is formed on one water/oil repellent-treated surface.