Water- and oil-repellent

A water- and oil-repellent comprising a copolymer comprising:

• (a) a fluoroalkyl group-containing monomer having a melting point of 60 to 80° C. in the state of a homopolymer, wherein the fluoroalkyl group-containing monomer (a) is a compound represented by the general formula:
• Rf—R1—X—R2C═CH2
• wherein Rf is a C3 to C20 straight-chain fluoroalkyl group, R1 is a C1 to C10 straight-chain or branched alkylene group, R2 is a hydrogen atom or a methyl group, and X is —O—C(═O)— or SO2—N(A1)—A2— in which A1 is a C1 to C4 alkyl group and A2 is a direct bond or —A3—O—C(═O)— in which A3 is a C1 to C4 alkylene group;
• and
• (b) a hydrophilic group-containing monomer, wherein the hydrophilic group-containing monomer (b) is a compound represented by the general formula:
• CH2═CR3COO—(R4O)n—R5
• wherein R3 and R5 represent a hydrogen atom or a methyl group;
• R4 represents a C2 to C6 alkylene group;
• and n is an integer of 1 to 50;
• and
• wherein when the fluoroalkyl group-containing monomer (a) is CF3CF2(CF2CF2)3CH2CH2OCOCH═CH2, the hydrophilic group-containing monomer (b) is not CH2═C(CH3)COO(CH2CH2O)9CH3.