Method for eliminating or preventing the brightening effects of anionic optical brighteners

Claim 1

A method of eliminating the brightening effect produced by or preventing the brightening effect from being produced by an anionic optical brightener on material comprising applying to the material substrate a water-soluble acid addition salt of quaternary ammonium salt of a compound produced by the acylation of an excess of a polyethylenepolyamine of formula, H(HN--CH.sub.2 --CH.sub.2).sub.p --NH.sub.2 in which p is an integer 2 to 5, with isophthalic or terephthalic acid or a functional derivative thereof in a molar ratio exceeding 1.5:1, subsequently cyclizing the product to afford imidazoline groups, and optionally reacting the product further by: a) full alkylation, b) partial alkylation followed by acylation in a molar ratio of initial to present acylating agent of 1:0.3 to 1:1.0, with a bifunctional acylating agent which is a saturated aliphatic dicarboxylic acid of formula, HOOC--(CH.sub.2).sub.q --COOH in which q is an integer 1 to 6, or a functional derivative thereof, or a functional derivative of carbonic acid, (c) acylation as described above with respect to (b), (d) acylation as described above with respect to (b) followed by alkylation, or (e) partial alkylation, which alkylation or quaternary ammonium salt formation is effected with an alkylating agent yielding a methyl, ethyl or phenyl- or naphthyl-substituted methyl or ethyl group, and which quaternary ammonium salt does not contain a nitrogen atom bearing more than two phenyl- or naphthyl-substituted methyl or ethyl groups.

Claim 2

A method of eliminating the brightening effect produced by or preventing the brightening effect from being produced by an anionic optical brightener on material comprising applying to the material substrate a water-soluble acid addition salt of quaternary ammonium salt of a compound produced by the acylation of an excess of a polyethylenepolyamine of formula, H(HN--CH.sub.2 --CH.sub.2).sub.p --NH.sub.2 in which p is an integer 2 to 5, with isophthalic or terephthalic acid or a functional derivative thereof in a molar ratio exceeding 1.5:1, subsequently cyclizing the product to afford imidazoline groups, and optionally reacting the product further by: a) full alkylation, b) partial alkylation followed by acylation in a molar ratio of initial to present acylating agent of 1:0.3 to 1:1.0, with a bifunctional acylating agent which is a saturated aliphatic dicarboxylic acid of formula, HOOC--(CH.sub.2).sub.q --COOH in which q is an integer 1 to 6, or a functional derivative thereof, or a functional derivative of carbonic acid, (c) acylation as described above with respect to (b), (d) acylation as described above with respect to (b) followed by alkylation, or (e) partial alkylation, which alkylation or quaternary ammonium salt formation is effected with an alkylating agent yielding a methyl, ethyl or phenyl- or naphthyl-substituted methyl or ethyl group, and which quaternary ammonium salt does not contain a nitrogen atom bearing more than two phenyl- or naphthyl-substituted methyl or ethyl groups.