A polyorganosiloxane compound comprising: - at least one polyorganosiloxane group (a), - at least one quaternary ammonium group (b), - at least one terminal ester group (c), - at least one functional organic group (d), comprising one or more hydroxyl groups and at least one functional group selected from an ester group, an ether group and an amino group, and wherein the molar ratio of the quaternary ammonium groups (b) and the terminal ester groups (c) is less than 100:15. said polyorganosiloxane compound comprises at least one unit of the formula: [-CH 2 -X-CH 2 -D-] wherein D is selected from the group consisting of: -N + R 2 -, -N + R 2 -Y-N + R 2 -, a saturated or unsaturated mono or diquaternary heterocycle of the formulae and and an aromatic ammonium heterocycle of the formula wherein X is at least one group X 1 and at least one group X 2, that is, at least one group X 1 and at least one group X 2 is present wherein X 1 is a difunctional organic group, comprising three or more hydroxyl groups and at least one functional group selected from the group consisting of an ester group, an ether group and an amino group, and wherein said group X 1 does not comprise a polydiorganosiloxane group, X 2 is a difunctional organic group, comprising at least one polydiorganosiloxane group, R can be the same or different is selected from monovalent organic groups having up to 22 carbon atoms and optionally one or more heteroatoms, Y is a difunctional organic group optionally comprising one or more heteroatoms. - at least one polyorganosiloxane group (a), - at least one quaternary ammonium group (b), - at least one terminal ester group (c), - at least one functional organic group (d), comprising one or more hydroxyl groups and at least one functional group selected from an ester group, an ether group and an amino group, and wherein the molar ratio of the quaternary ammonium groups (b) and the terminal ester groups (c) is less than 100:15. said polyorganosiloxane compound comprises at least one unit of the formula: [-CH 2 -X-CH 2 -D-] wherein D is selected from the group consisting of: -N + R 2 -, -N + R 2 -Y-N + R 2 -, a saturated or unsaturated mono or diquaternary heterocycle of the formulae and and an aromatic ammonium heterocycle of the formula wherein X is at least one group X 1 and at least one group X 2, that is, at least one group X 1 and at least one group X 2 is present wherein X 1 is a difunctional organic group, comprising three or more hydroxyl groups and at least one functional group selected from the group consisting of an ester group, an ether group and an amino group, and wherein said group X 1 does not comprise a polydiorganosiloxane group, X 2 is a difunctional organic group, comprising at least one polydiorganosiloxane group, R can be the same or different is selected from monovalent organic groups having up to 22 carbon atoms and optionally one or more heteroatoms, Y is a difunctional organic group optionally comprising one or more heteroatoms. -N + R 2 -, -N + R 2 -Y-N + R 2 -, a saturated or unsaturated mono or diquaternary heterocycle of the formulae and and an aromatic ammonium heterocycle of the formula wherein X is at least one group X 1 and at least one group X 2, that is, at least one group X 1 and at least one group X 2 is present wherein X 1 is a difunctional organic group, comprising three or more hydroxyl groups and at least one functional group selected from the group consisting of an ester group, an ether group and an amino group, and wherein said group X 1 does not comprise a polydiorganosiloxane group, X 2 is a difunctional organic group, comprising at least one polydiorganosiloxane group, R can be the same or different is selected from monovalent organic groups having up to 22 carbon atoms and optionally one or more heteroatoms, Y is a difunctional organic group optionally comprising one or more heteroatoms. X is at least one group X 1 and at least one group X 2, that is, at least one group X 1 and at least one group X 2 is present wherein X 1 is a difunctional organic group, comprising three or more hydroxyl groups and at least one functional group selected from the group consisting of an ester group, an ether group and an amino group, and wherein said group X 1 does not comprise a polydiorganosiloxane group, X 2 is a difunctional organic group, comprising at least one polydiorganosiloxane group, R can be the same or different is selected from monovalent organic groups having up to 22 carbon atoms and optionally one or more heteroatoms, Y is a difunctional organic group optionally comprising one or more heteroatoms.