Cover-gasket assembly for hard disk device

A cover-gasket assembly for a hard disk device, comprising a gasket applied to a predetermined position of a cover for the hard disk device, wherein said gasket is formed essentially of a cured product of a liquid fluorosilicone rubber composition having a water vapor permeability coefficient of 40 g.mm/m.sup.2.24 hr or below, wherein said liquid fluorosilicone rubber composition comprises:

• (a) a fluorine-containing diorganopolysiloxane having the following general formula (1):
• ##STR7## wherein R.sup.1 and R.sup.2 may be the same or different from each other and are each an unsubstituted or substituted monovalent hydrocarbon group which does not have aliphatic unsaturated bonds, R.sup.3 is a monovalent aliphatic unsaturated hydrocarbon group, R.sup.4 is a divalent hydrocarbon group having no aliphatic unsaturated bonds or is a group represented by the following general formula (2):
• --R.sup.5 --O--R.sup.6 -- (2)
• wherein R.sup.5 and R.sup.6 are each a divalent hydrocarbon group having no aliphatic unsaturated bonds, Rf is a perfluoroalkyl group of from 4 to 10 carbon atoms or a perfluoroalkyl ether group of from 5 to 15 carbon atoms, X is a hydrogen atom or a group represented by the following general formula (3):
• --Si(R.sup.7).sub.3 (3)
• wherein R.sup.7 may be the same or different from each other and are each an unsubstituted or substituted monovalent hydrocarbon group, l and m are each an integer of 1 or above, and n is an integer of 0 or above, and further, wherein said fluorine-containing diorganopolysiloxane comprises cyclic siloxanes having a molecular weight of 3,000 or below in a concentration of 0.01% by weight or below;
• (b) a filler;
• and
• (c) a curing agent.