Antistatic agent, antistatic film and articles coated with antistatic film

1. An antistatic agent, comprising a water-soluble electroconductive polymer, a solvent and a water-soluble polymer,

wherein the water-soluble polymer is a water-soluble polymer having a polypeptide structure, said water-soluble polymer having the polypeptide structure consisting of a protein hydrolysate having a number average molecular weight of 4000 or less,

wherein the water-soluble electroconductive polymer is a π-conjugated conductive polymer having a Bronsted acid group or a salt thereof, and

wherein the Bronsted acid group is a sulfonic acid group.

2. The antistatic agent as claimed in claim 1 , wherein the protein hydrolysate has an amino acid residue (10) a as repeating unit structure:

—(N(—R′)—CH(—R)—C(═O))—  (10)a

wherein R and R′ each independently represents a substituent constituting an amino acid residue and when R′ is a hydrogen atom, R independently represents a substituent constituting an amino acid residue and when R′ is not a hydrogen atom, R and R′ jointly form a nitrogen-containing ring which may be substituted with a hydroxyl group.

3. The antistatic agent as claimed in claim 1 , further comprising a surfactant.

4. The antistatic agent as claimed in claim 1 , wherein the amount of the water-soluble electroconductive polymer is from 0.1 to 20 mass %, the amount of the water-soluble polymer having the polypeptide structure is 0.0001 to 10 mass % and the amount of the solvent is from 70.0 to 99.8 mass %.

5. The antistatic agent as claimed in claim 1 , wherein the amount of the water-soluble electroconductive polymer is from 0.1 to 20 mass %, the amount of the water-soluble polymer having a polyvinyl structure is 0.0001 to 10 mass % and the amount of the solvent is from 70.0 to 99.8 mass %.

6. The antistatic agent as claimed in claim 3 , wherein the amount of the water-soluble electroconductive polymer is from 0.1 to 20 mass %, the amount of the water-soluble polymer having the polypeptide structure is 0.0001 to 10 mass %, the amount of the surfactant is from 0.0001 to 2 mass % and the amount of the solvent is from 68.0 to 99.8 mass %.

7. The antistatic agent as claimed in claim 3 , wherein the amount of the water-soluble electroconductive polymer is from 0.1 to 20 mass %, the amount of the water-soluble polymer having a polyvinyl structure is 0.0001 to 10 mass %, the amount of the surfactant is from 0.0001 to 2 mass % and the amount of the solvent is from 68.0 to 99.8 mass %.

8. The antistatic agent as claimed in claim 1 , wherein the water-soluble electroconductive polymer includes a chemical structure represented by formula (1):

in the formula, m and n each independently represents 0 or 1, X represents any one of S, N—R 1 and O, (R 1 represents a group selected from the group consisting of a hydrogen atom, a linear or branched, saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms, a phenyl group and a substituted phenyl group and O, A represents an alkylene or alkenylene group wherein two or more double bonds may be present, having 1 to 4 carbon atoms which has at least one substituent represented by —B—SO 3 − M + and may have other substituents, B represents —(CH 2 ) p —(O) q —(CH 2 ) r —, p and r each independently represents 0 or an integer of 1 to 3, q represents 0 or 1, and M + represents a hydrogen ion, an alkali metal ion or a quaternary ammonium ion.

9. The antistatic agent as claimed in claim 1 , wherein the water-soluble electroconductive polymer includes a chemical structure represented by formula (2):

in the formula, R 2 to R 4 each independently represents a hydrogen atom, a linear or branched, saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms, a linear or branched, saturated or unsaturated alkoxy group having 1 to 20 carbon atoms, a hydroxyl group, a halogen atom, a nitro group, a cyano group, a trihalomethyl group, a phenyl group, a substituted phenyl group or —B—SO 3 − M + group, B represents —(CH 2 ) p —(O) q —(CH 2 ) r —, p and r each independently represents 0 or an integer of 1 to 3, q represents 0 or 1, and M + represents a hydrogen ion, an alkali metal ion or a quaternary ammonium ion.

10. The antistatic agent as claimed in claim 1 , wherein the water-soluble electro conductive polymer includes a chemical structure represented by formula (3):

in the formula, R 5 represents a hydrogen atom, a linear or branched, saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms, a linear or branched, saturated or unsaturated alloy group having 1 to 20 carbon atoms, a hydroxyl group, a halogen atom, a nitro group, a cyano group, a trihalomethyl group, a phenyl group, a substituted phenyl group or —B—SO 3 − M + group, B represents —(CH 2 ) p —(O) q —(CH 2 ) r —, p and r each independently represents 0 or an integer of 1 to 3, q represents 0 or 1, and M + represents a hydrogen ion, an alkali metal ion or a quaternary ammonium ion.

11. The antistatic agent as claimed in claim 1 , wherein the water-soluble electroconductive polymer includes a chemical structure represented by formula (4):

in the formula, R 6 and R 7 each independently represents a hydrogen atom, a linear or branched, saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms, a linear or branched, saturated or unsaturated alkoxy group having 1 to 20 carbon atoms, a hydroxyl group, a halogen atom, a nitro group, a cyano group, a trihalomethyl group, a phenyl group, a substituted phenyl group or a —B—SO 3 − M + group, R 8 represents a monovalent group selected from a hydrogen atom, a linear or branched, saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms, phenyl group and a substituted phenyl group, B represents —(CH 2 ) p —(O) q —(CH 2 ) r —, p and r each independently represents 0 or an integer of 1 to 3, q represents 0 or 1, and M + represents a hydrogen ion, an alkali metal ion or a quaternary ammonium ion.

12. The antistatic agent as claimed in claim 9 , wherein the water-soluble electroconductive polymer is a polymer having 5-sulfoisothianaphthene-1,3-diyl.