Fluorinated compound and fluorinated polymer

#The present invention relates to a novel fluorinated compound and a fluorinated polymer obtainable by polymerizing it.

#As a technique to simultaneously impart water repellency and oil repellency to a surface, it is known to treat an article with an organic solvent solution or aqueous dispersion of a polymer comprising polymerized units of a polymerizable monomer containing a polyfluoroalkyl group (a group having a structure wherein at least two and at most all of hydrogen atoms in an alkyl group are substituted by fluorine atoms, such a polyfluoroalkyl group will be hereinafter referred to as an “Rf group”) in its molecule, or a copolymer of such a monomer with another monomer.

#Such water/oil repellency is attributable to formation of “a low surface energy surface” having a low critical surface tension on the surface due to a surface orientation of Rf groups on the coating film. It has been taken for granted that in order to attain both water repellency and oil repellency, orientation of Rf groups at the surface is important, and in order to realize the surface orientation of Rf groups, it is necessary to have constituting units derived from a monomer having a perfluoroalkyl group (a group having a structure wherein all of hydrogen atoms in an alkyl group are substituted by fluorine atoms, such a perfluoroalkyl group will be hereinafter referred to as an “RF group”) with at least 8 carbon atoms in the polymer.

#Now, embodiments of the present invention will be described. In this specification, a (meth)acrylate means an acrylate or a methacrylate. Likewise, (meth)acrylic acid means acrylic acid or methacrylic acid.

#<Fluorinated Compound of the Present Invention>

#The fluorinated compound of the present invention is a fluorinated compound which, as shown in the following formula (I), has an acryloyloxy group (which may be substituted) as a polymerizable group at its one terminal and an RF group with at most 6 carbon atoms at the other terminal and which has, as a bivalent linking group to link the two, a linking group of a structure having two benzene rings bonded by a group containing an etheric oxygen atom. A fluorinated polymer obtainable by polymerizing the fluorinated compound of the present invention having such a molecular structure, has a water/oil repellency and also has a high durability whereby the water/oil repellency will not be impaired by e.g. use for a long period of time. CH2═C(M)COO(CH2)nPhXPhZCrF2r+1  (I) (in the formula (I), M is a hydrogen atom, a methyl group or a halogen atom, n is an integer of from 0 to 2, Ph is a phenylene group, X is CH2O or OCH2, Z is a single bond, a C1-4 alkylene group containing an etheric oxygen atom, or COO(CH2)m (wherein m is an integer of from 1 to 4), and r is an integer of from 1 to 6).