WATER/OIL REPELLENT COMPOSITION AND METHOD FOR ITS PRODUCTION

1 . A water/oil repellent composition which comprises a copolymer having structural units based on the following monomer (a), structural units based on the following monomer (b) and structural units based on the following monomer (c), and a medium, wherein the molar ratio of the structural units based on the monomer (a) to the structural units based on the monomer (b) (i.e. (a)/(b)) is at least 1:

monomer (a): vinyl chloride;

monomer (b): a vinyl ether having no polyfluoroalkyl group and having a crosslinkable functional group; and

monomer (c): a monomer having a polyfluoroalkyl group.

2 . The water/oil repellent composition according to claim 1 , wherein the monomer (c) is a compound represented by the following formula (1):

(Z—Y) n X  (1)

wherein Z is a C 1-6 polyfluoroalkyl group or a group represented by the following formula (2), Y is a bivalent organic group or a single bond, n is 1 or 2, and X is, when n is 1, any one of the groups represented by the following formulae (3-1) to (3-5) and, when n is 2, any one of the groups represented by the following formulae (4-1) to (4-4):

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

wherein i is an integer of from 1 to 6, j is an integer of 0 to 10, and each of X 1 and X 2 which are independent of each other is a fluorine atom or a trifluoromethyl group;

—CR═CH 2   (3-1)

—C(O)OCR═CH 2   (3-2)

—OC(O)CR═CH 2   (3-3)

—OCH 2 -φ-CR═CH 2   (3-4)

—OCH═CH 2   (3-5)

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

—CH[—(CH 2 ) m CR═CH 2 ]  (4-1)

—CH[—(CH 2 ) m C(O)OCR═CH 2 ]  (4-2)

—CH[—(CH 2 ) m OC(O)CR═CH 2 ]  (4-3)

—OC(O)CH═CHC(O)O—  (4-4)

where R is a hydrogen atom, a methyl group or a halogen atom, and m is an integer of from 0 to 4.

3 . The water/oil repellent composition according to claim 1 , wherein the monomer (c) is a (meth)acrylate having a C 4-6 perfluoroalkyl group.

4 . The water/oil repellent composition according to claim 1 , wherein the crosslinkable functional group in the monomer (b) is a hydroxy group, an epoxy group or an amino group.

5 . The water/oil repellent composition according to claim 1 , wherein the copolymer further has structural units based on the following monomer (d):

monomer (d): a (meth)acrylate having no polyfluoroalkyl group and having a C 12-30 alkyl group.

6 . The water/oil repellent composition according to claim 1 , wherein the copolymer further has structural units based on the following monomer (e):

monomer (e): a monomer having no polyfluoroalkyl group and having a crosslinkable functional group (provided that the monomer (b) is excluded).

7 . A method for producing a water/oil repellent composition, which comprises polymerizing a monomer mixture comprising the following monomer (a), the following monomer (b) and the following monomer (c) in a medium in the presence of a surfactant and a polymerization initiator, wherein the molar ratio of the monomer (a) to the monomer (b) (i.e. (a)/(b)) is at least 1:

monomer (a): vinyl chloride;

monomer (b): a vinyl ether having no polyfluoroalkyl group and having a crosslinkable functional group; and

monomer (c): a monomer having a polyfluoroalkyl group.

8 . The method for producing a water/oil repellent composition according to claim 7 , wherein the monomer (c) is a compound represented by the following formula (1):

(Z—Y) n X  (1)

wherein Z is a C 1-6 polyfluoroalkyl group or a group represented by the following formula (2), Y is a bivalent organic group or a single bond, n is 1 or 2, and X is, when n is 1, any one of the groups represented by the following formulae (3-1) to (3-5) and when n is 2, any one of the groups represented by the following formulae (4-1) to (4-4):

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

wherein i is an integer of from 1 to 6, j is an integer of 0 to 10, and each of X 1 and X 2 which are independent of each other is a fluorine atom or a trifluoromethyl group;

—CR═CH 2   (3-1)

—C(O)OCR═CH 2   (3-2)

—OC(O)CR═CH 2   (3-3)

—OCH 2 -φ-CR═CH 2   (3-4)

—OCH═CH 2   (3-5)

wherein R is a hydrogen atom, a methyl group or a halogen atom, and φ is a phenylene group;

—CH[—(CH 2 ) m CR═CH 2 ]—  (4-1)

—CH[—(CH 2 ) m C(O)OCR═CH 2 ]—  (4-2)

—CH[—(CH 2 ) m OC(O)CR═CH 2 ]—  (4-3)

—OC(O)CH═CHC(O)O—  (4-4)

where R is a hydrogen atom, a methyl group or a halogen atom, and m is an integer of from 0 to 4.

9 . The method for producing a water/oil repellent composition according to claim 7 , wherein the monomer (c) is a (meth)acrylate having a C 4-6 perfluoroalkyl group.

10 . The method for producing a water/oil repellent composition according to claim 7 , wherein the crosslinkable functional group in the monomer (b) is a hydroxy group, an epoxy group or an amino group.

11 . The method for producing a water/oil repellent composition according to claim 7 , wherein the monomer mixture further contains the following monomer (d):

monomer (d): a (meth)acrylate having no polyfluoroalkyl group and having a C 12-30 alkyl group.

12 . The method for producing a water/oil repellent composition according to claim 7 , wherein the monomer mixture further contains the following monomer (e):

monomer (e): a monomer having no polyfluoroalkyl group and having a crosslinkable functional group (provided that the monomer (b) is excluded).