Patent ID: 7846876

Claim:
A surfactant composition comprising a cationic surfactant as compound (A), at least one compound as compound (B) selected from the group consisting of anionic aromatic compounds and bromide compounds, and a cationic polymer (C), wherein compounds (A) and (B) are selected for the surfactant composition when meeting the condition wherein a combination of the compounds (A) and (B) ensures that the viscosity at 20° C. of a solution prepared by mixing an aqueous solution SA, which solution has a viscosity of 100 mPa·s or less at 20° C., of compound (A) with an aqueous solution SB, which solution has a viscosity of 100 mPa·s or less at 20° C., of compound (B) in a ratio by weight of 50/50 is at least two times the viscosity of any one of the aqueous solutions at 20° C. before being mixed; wherein the cationic polymer (C) has a cation density of from 0.5 to 10 meq/g and a molecular weight of 1,000 to 500,000; wherein the cationic polymer (C) comprises a cationic nitrogen that is bonded with at least one group selected from the group consisting of an alkyl group having 1 to 22 carbon atoms, a polyoxyalkylene group containing an oxyalkylene group having 2 to 8 carbon atoms, a hydrogen atom and a group represented by the following formula (1): wherein R 1 to R 5 , which may be the same or different, respectively represent a hydrogen atom or an alkyl or alkenyl group having 1 to 22 carbon atoms, Z represents —O— or —NY—, wherein Y represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and n denotes a number from 1 to 10, provided that R 1 and R 3 may be incorporated into the polymer structure and in this case, R 1 and R 3 are not present; and wherein the cationic polymer (C) has a structure derived from a monomer selected from at least one or more monomers selected from the group consisting of a (meth)acrylic acid monomer having a cationic group and a diallyldialkylamine type monomer.