Antimicrobial composition comprising a polyimide

An aqueous antimicrobial cleaning composition comprising:

• i) from 0.02% to 2.50% by weight of the composition of a biocidal agent, wherein said biocidal agent comprises a quaternary ammonium biocidal compound and wherein the quaternary ammonium biocidal compound is a mixture comprising:
• from about 30% to about 50%, by weight of the mixture of N-alkyl dimethyl benzyl ammonium chloride, from about 20% to about 40% by weight of the mixture of N-octyl decyl dimethyl ammonium chloride, from about 5% to about 25% by weight of the mixture of di-n-decyl dimethyl ammonium chloride, and about 5% to about 25% by weight of the mixture of di-n-octyl dimethyl ammonium chloride;
• and
• ii) from about 0.1 to about 2% by weight of the composition a polyimide;
• wherein the polyimide comprises at least one structural unit (A1), at least one structural unit (A2), at least one structural unit (A3), and optionally one additional structural unit (A4)
• wherein
• R1 stands for an optionally heterofunctionalized alkyl radical;
• R2 stands for an optionally heterofunctionalized alkyl radical other than R1;
• and
• R3, independently of one another, stands for H, or an optionally heterofunctionalized alkyl radical other than R1 and R2.