Patent ID: 7566480

Claim:
Method of treatment comprising contacting porous stone with a composition comprising: (i) a fluorinated oligomer having a weight average molecular weight of not more than 70,000 g/mol and comprising repeating units derived from one or more hydrocarbon monomers and one or more fluorinated monomers represented by the formula: R f —X t -E 1 wherein R f represents a perfluorinated aliphatic group having 3 or 4 carbon atoms, X represents a non-fluorinated linking group, t is 0 or 1 and E 1 represents an ethylenically unsaturated group; and wherein the amount of repeating units derived from said fluorinated monomers is more than 50 mole % of the total amount of repeating units; (ii) a liquid dispersing or dissolving said fluorinated oligomer, said liquid comprising an organic solvent in an amount of at least 70% by weight based on the total amount of liquid; wherein the fluorinated oligomer does not contain a silyl group having one or more hydrolysable groups, and wherein said fluorinated oligomer is contained in said composition in an amount of 1 to 20% by weight based on the total weight of the composition.