Zigarettenfilter

A cigarette filter comprises a fibrous base material impregnated with 0.01% to 25% based on the weight of the base material of a water-insoluble compound having a vapour pressure between 0 mm. and 40 mm. Hg. at 25 DEG C., the compound being a polymer of N-vinyl-5-methyl-2-oxazolidinone or copolymer thereof with another vinyl polymer, the copolymers containing at least 25% by weight of the N-vinyl-5-methyl-2-oxazolidinone nucleus, or a polyglycol represented by one of the following formulae:-(1) HXOH, (2) R(XOH), (3) R-Nb (XOH)2b and wherein R is a saturated hydrocarbon radical containing from 2 to p 6 carbon atoms, X is a polymeric chain having the formula-[OR1]z-, R1 being an alkylene radical containing from 2 to 6 carbon atoms, a is 1, 2 or 3 and b is 1 or 2, said polyglycol containing from 10 to 37% ether oxygen. The fibrous base material is a cellulose derivative additionally impregnated with a plasticizer which is a solvent for the water-insoluble compound. The water-insoluble compound preferably has a vapour pressure of from 0 mm. to 1 mm. Hg. at 25 DEG C., and is present in an amount from 0.2%-3% based on the weight of the base material. The polyglycol may have the formula C3H5(XOH)3 wherein X is a polymeric chain having the formula -[OC3H6]z-. Quantitative examples are given and examples of suitable compounds including polyglycols are given in Table I.